figure of the hook has a very long base and shows only a single tooth above the main fang
(and resembles that of T. cincinnatus).
The tube is composed of secretion to which fragments of shells or entire uni- and
bivalves, pieces of heart-urchin, fragments of Cellepora, and numerous other structures
are attached, and it much resembles that of Thelepus cincinnatus, var. andreanse. Lepido-
notus squamatus occurred as a commensal in the tube of an example dredged in 81 fathoms
by the “ Porcupine ” off Cape Finisterre ; and Mr. Southern mentions another commensal,
viz., Polynde scolopendrina, in Clew Bay.
Reproduction. —An example from Lussin in the Adriatic forwarded by Prof.. Grube
had its coelom crowded with large ova. It was probably procured in summer. Mature
specimens (as T. setosus) are found with pale salmon-coloured eggs in August (Southern).
Thelepus setosus, De Quatrefages (1865) and other authors, seems to be allied in the
closest manner to this species. Descriptions do not enable a definite distinction to be
made, and the same result ensues on the examination of specimens kindly forwarded
by Mr. Southern from Blacksod Bay. No clear separation could be made.
Fauvel recently has studied numerous specimens of Thelepus spectdbilis, from the
Falkland Islands, and found them identical with the Thelepus setosus of De Quatrefages,
so common near Cherbourg. He queries if the latter is not T. triserialis, although the
hooks are slightly different. ' The conclusion had already been drawn from descriptions
that they could not be separated. This author, further, is of opinion that the Neottis
antarcticus, McIntosh, is the same form, but the marked shortness and depth of the
base of the hooks, the different outline below the stud near the tip, as well as the
frequent presence of a larger spine on the crown in lateral view in Thelepus setosus
are noteworthy, though a margin is necessary for variation.
This form occurs from Polperro in preparation 62 . 7 . 12_. 45 in the British Museum.
It is labelled “ TerebeUa nebulosa.”
Genus CLIII.—Streblosoma, Sars, 1871.
Cephalic lobe truncate anteriorly, and the dorsal collar is devoid of eye-specks in the
preparations. Supra-oral arch flat, and the post-oral lip longer than in Thelepus. Body
enlarged anteriorly, but gradually diminishing to a slender tail. Branchige three pairs
of simple filaments on the second, third and fourth segments, but] their position and
relationship to the setigerous processes differ from those of Thelepus. The bristles
commence on the second segment, and differ from those of Thelepus by their great length
and more lustrous condition. Hooks commence on the fifth segment, are smaller than in
Thelepus, uniserial, with two prominent teeth above the main fang; a process for the
ligament occurs on the anterior outline and the prow is prolonged downward and forward
beyond it. The anterior nephridia (in the fifth segment) are smaller than the posterior,
which appear to increase from the diaphragm backward. Tube of muddy sand in fine
grains. The genus extends to America (Verrill).
Verrill1 (1900) observes that the title Grymsea is preoccupied, and that therefore
1 ‘Ti’ans. of the Connect. Acad.,’ vol. x, p. 661.
Streblosoma, Sars, is the only tenable name for the genus. In this he was followed
by Treadwell.1
1. Streblosoma bairdi, Malmgren, 1865. Plate CXXVT, figs. 7 7 a bristle and hook.
Specific Characters.—Cephalic lobe as in Thelepus. Three pairs of simple branchiaa
Body 2^ inches or more in length, with about thirty-two flattened and lohate setigerous
processes, the region behind having only uncinigerous processes. The flattened rows
of bristles are twisted like a screw propeller. Nephridia in the third, fourth, fifth,
sixth and seventh segments. Bristles about ninety pairs, very long, striated, gently
tapered beyond the skin, and with narrow wings. TJie shorter forms are more slender
and alternate with the others; though on the dorsal edge long bristles and on the
ventral edge slender bristles occur. Hooks distinguished by having two distinct prongs
above the great fang, and the stud on t h |‘; anterior outline leaves it at an obtuse
angle, the prow being produced below it. Tube rather thick, of grey mud and sand.
Malmgren named it after the genial and distinguished Dr. W. Baird of the British Museum.
Synonyms.
1865. Grymsea Bairdi, Malmgren. Nord. Hafs.-Annul., p. 388; Tab. xix, fig. 69.
1867. „ „ idem. Annul. Polych., p. 219.
1869.- - „ „ McIntosh. Trans. Roy. Soc. Edin., vol. xxv> p. 424.
1871. Streblosoma cochleatum, G. 0. Sars. Yid. Selsk. Skrift. Kristiania, p. 414.
1874. „ ' ' , » Malm. Annul. Goteb., p. 99.
1876. Neottis antarctica, McIntosh. Ann. Nat. Hist., ser. 4, vol. xvii, p. 321.
. }} }> idem. Transit. Yenus Exped., p. 4, pi. xv, figs. 14 and 15.
1877. Thelepus Mclntoshii, Grube. Monatsber. Konigl. Akad. Wiss. Berlin, p. 544.
1879. TerebeUa Bavrdii, Tauber. Annul. Danica, p. 134.
„ cochleatum, idem. Ibid., p. 133.
1883. Grymsea Bairdi, Levinsen. Yidensk. Meddel., p. 177.
. „ Streblosoma cochleatum, idem. Ibid., p. 177.
1885. Neottis antarctica, McIntosh. Rep. “ Challenger,” vol. xii, p. 472, pi. lii, fig. 1.
1894. Streblosoma cochleatum, Bidenkap. Christiania Yidenskab.-Selsk. Forhandlinger, No. 10, p. 131.
1896. „ „ Appellof. Bergens Museum, Aarbog, No. 13 (1894—96), p. 12.
1897. Gh'ymsea Bairdi and Streblosoma cochleatum, Michaelsen. Polych. deutsch. Meere, p. 174.
1901. Thelepus spectdbilis, Pratt. Mem. Manchester Lit. and Philos. Soc., vol. xlv, No. 13, p. 14.
„ ? Grymsea spiralis, Whiteaves. Mar. Invert. E. Canada, p. 73.
1902. Thelepus antarcticus, Willey. “ Southern Cross,”- p. 278.
1906. „ thoracicus, Gravier. Nouv. Arch. Mus. d’Hist. Nat., ser. 4, t. viii, p. 218, pi. iv, figs.
228 and 229.
1912. Grymsea Bairdi, Wollebmk. Yid. Selsk. Skrift. Christiania, No. 18, p. 88, pi. xx, figs. 8 and
9, pi. xxix, fig. 2,
„ „ Meyer. Inaug. Dissert. Kiel, p. 49.
1914. Thelepus spectdbilis and thoracicus, Augener. Fauna S.W. Australia, Bd. v, Jena p. 98.
1915. Grymsea Bairdi, McIntosh. Ann. Nat. Hist., ser. 8, vol. xv, p. 31.
Thelepus triserialis, idem. Ibid., ser. 8, vol. xv, p. 29.
1 ‘Bull. Amer. Mus. Nat. Hist./ vol. xxx, p. 11, 1911.