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CEPHALOPODA. OMMASTREPHES EBLANÆ, Ball. Mr. Hoyle has recently re-described this rare Cephalopod,
a specimen of which was sent to him from the neighbourhood by Mr. Cunningham. (Jour. M. B. A. ii. 1891,
p. 189.) ILLEX COINDETI, Vérany. This species, more generally known as Ommastrephes sagit
tatus, has been brought in by trawlers on several occasions. ROSSIA MACROSOMA, Della Chiaje. This is yet another species which I believe has not
hitherto been recorded from our western shores. I
Total length from mouth to posterior extremity 9 cm.
5.6 cm. Breadth of head across the eyes .
3.5 cm. Maximum breadth of mantle, excluding fins 5 cm.
including fins 8 Length of ventral arms
6 tentacular arms
ENTOMOSTRACA. Mr. Bourne, in his “Notes on the Genus Monstrilla" (Quart.
Jour. Micr. Science, xxx, 1890, p. 565), has recorded the capture of three different species of this anomalous genus at Plymouth, viz., M. rigida (Thompson), M. Dana (Claparède), and M. longispinosa. The last species is new to science, and is described by Mr. Bourne as peculiar in having the first of the two abdominal segments as long as the preceding thoracic segment, and in the possession of a single two-branched genital seta, which is half as long again as the whole body of the animal.
MALACOSTRACA. IDOTEA PARALLELA, Bate and Westwood. I found a single individual of this species of Isopod on
June 8th last, when it was trawled among weeds in shallow water on a sandy bottom. It was inhabiting a small piece of the stem of a dead Zostera, from which it protruded only the anterior portion of its body; and I observed it walk about, with its "house” behind it, exactly like a common Caddis worm. It was of torpid habits, but could swim in the ordinary way when removed from its protecting tube. It is probably an immature individual, for the first pair of legs (pereiopods)
are not at all enlarged. ANTHURA GRACILIS, Montagu. I dredged a specimen on June 29th last in Plymouth
Sound which possesses first antennæ of a form remarkably different from that which was described by Bate and Westwood as typical of the species. They are immense structures for so small and delicate an animal. Their length exceeds that of the head and first segment of the pereion together; and the flagellum consists of nine joints, each of which is provided with a dense
circlet of long hairs near its distal extremity. I believe that the specimen whose peculiarities I have
described is the male of Anthura gracilis, and that the description given in the “Sessile-eyed Crustacea” is applicable in its entirety only to female individuals of the species. I have compared my specimen with two individuals in a collection of the late Mr. Spence Bate which is now under our charge at the Plymouth laboratory, and I find a very close agreement in all points except those which have been enumerated, and which are probably therefore sexual.
ENTEROPNEUSTA. BALANOGLOSSUS SALMONEUS, Giard. An imperfect individual, probably belonging to this species,
was dredged inside the east end of the great breakwater, on July 31st, 1889, the only capture of Balanoglossus,
I believe, that has yet been made on the British coasts. 1 Since writing the above, I find that the very condition of the antennæ which I have described has been predicted by Norman and Stebbing to occur in adult males of this species. They have described a young male provided with enlarged, although smooth, antennæ, and add: “We think it probable ... that when quite matured, the antennæ would have the flagella even more developed and ciliated.” (Trans. Zool. Soc. xii. 1886, p. 123, pl. xxv.) It should be noticed, however, that the flagellum shown in their figure iii. D, consists of twice as many joints as does the flagellum in my specimen ; but this may possibly have been due to a slight error in the drawing.
In another rather larger specimen since obtained (5 mm. in length) the flagella are 12-jointed, and the antennæ are as long as the head and first two segments of the pereion.
TUNICATA. PYCNOCLAVELLA AURILUCENS, Garstang. This is a very beautiful little Compound Ascidian, a near
ally of Clavelina, that I described in the journal of the Association in 1891. (Vol. ii. p. 53.) It has not yet been discovered in any other locality except the immediate neighbourhood of Plymouth, where two varieties are to be met with. Even at Plymouth, however, it is by no means common. The colonies are small in size, and consist of a number of pedunculated zooids which arise independently from a common encrusting base. The apertures of the zooids are plain and circular, not divided into lobes. The colour of the test is greenish, and each zooid is marked by a conspicuous streak along the line of the endostyle, either of a bright golden colour or opaque white. It inhabits very rocky ground, and is usually attached to irregular masses of Polyzoa and Annelid tubes
, or may form a thin carpet on the stems of Delesseria. ARCHIDISTOMA AGGREGATUM, Garstang. I first obtained this very interesting Compound Ascidian
in the summer of last year, when dredging in fifteen fathoms, two miles south of the Mewstone, and have since procured it in considerable abundance in Plymouth Sound. It was briefly described in the Annals of Natural History for October, 1891, and in the Zoologischer Anzeiger, No. 378, for the same year. It resembles the last species in having a common encrusting base, from which arise club-shaped zooids. The zooids are not infrequently quite independent of one another; but usually they are aggregated together so as to form little clumps of zooids, partially joined together by a common test. Each zooid possesses two distinct apertures, which are always six-lobed. The colonies are found encrusting shells and stones, and are usually rendered very inconspicuous by the adhesion of sand-grains. It is the most primitive of the true Distomidæ, and with Pycnoclavella almost bridges the gap between this family and the Clavelinidæ.
CEPHALOCHORDA. AMPHIOXUS LANCEOLATUS, Yarrell. The Lancelet has been dredged off the Mewstone on a
good many different occasions, and in its pelagic stage has been taken in the tow-net off the Eddystone, and close outside the Breakwater.
THE STONE ROWS OF DARTMOOR.
R. N. WORTH, F.G.S.
(Read at Plymouth, July, 1892.)
INTRODUCTION. The object of this paper is to reconsider in brief the twin questions of the origin and purpose of the most mysterious of the pre-historic monuments of Dartmoor, the rows of stones commonly known as avenues, parallelitha, or alignmentsnames we shall do well to discard in favour of the simple Saxon phrase stone rows, by which we first find them described in ancient documents.
It has been the misfortune of Dartmoor archæology to suffer from over-individualization. Thus Grimspound has been treated as exceptional in character because of its exceptionally perfect state, whereas it is but one enclosure of kindred type out of many. And so the special attention paid to the stone rows near Merivale Bridge is mainly responsible for the free use of the terms “avenues” and “parallelitha.” Had it been clearly seen that while, on the one hand, there were many instances of such structures consisting of single rows, so, on the other, the number of rows at times increased up to two and twenty, the inapplicability of the word “ avenues” would have been at once apparent. The essential feature is the row, not the number of rows; for although two are very commonly found, ones are as numerous on Dartmoor, and twos are really in a minority when compared with the general aggregate. So with the term "parallelitha”; it is correct enough up to a certain point; but there are partially double-membered rows, which never have been more complete; and there are sets of rows in which, so far from parallelism, there is marked and intentional divergence. “Alignments” is better than its companions; but here again the idea of straightness is imported, whereas some of these rows, as already stated, are divergent, while others are more irregularly curved. The simple word "row," however, has the merit of expressing neither less nor more than the actual facts, and it can be defined without delimitation to express precisely the peculiarities of each individual case. Moreover, it is uncontaminated by hasty speculation or unwise theory. I think it preferable also to the final alternative “line,” since it does not include the idea of absolute continuity.
Our special interest as an Association in these “ rows” lies in the fact that individual instances are more numerous on Dartmoor than in any other part of the world. Twenty-seven Dartmoor examples are noted in this paper : eleven single; eleven double; one partially doubled ; one double continued as a single; one group of three made up of a single and double side by side; one of three; and one of seven. Mr. Fergusson, in his Rude Stone Monuments, summed up all that was known up to 1872, and while there have been further discoveries since, I do not think that they have been in different fields. We get these rows in Devon (but not in Cornwall ), in Somerset, Wilts, Kent, Cumberland, Caithness, Carnac and elsewhere in Brittany, one example in Lombardy, and doubtful ascriptions in Spain and Denmark. They are not recorded for Wales or Ireland, or for any other part of the Continent, though reported from Persia and India. Hence, all things considered, these monuments may be studied most fully on Dartmoor.
DARTMOOR. We commence by a statement of the facts. I purpose first to give a description of the "stone rows" of Dartmoor and of their kindred elsewhere. The more important and exceptional of our local examples are dealt with most fully; and several of these have hitherto found no record, or have been very inadequately and incorrectly treated. The responsibility of the statements now made, where no authority is quoted, rests with the writer. Description given, we may proceed to draw some definite general conclusions, and pave the way for the solution of the problem, even should it be thought that solution cannot yet be reached.
And I should premise that the destruction of some of the
I "Remains of avenues are indeed said to have existed near Kilmarth, but the Rev. Mr. Lukis could find nothing approaching an avenue the eight stones called the “Nine Maidens, near St. Columb. Moreover, these average 68 feet apart, and bear no likeness to the true “rows."