88 THE VOYAGE OF H.M.S. CHALLENGER. 



Two specimens (one somewhat damaged) were obtained south of Halifax, Nova 

 Scotia, at Station 48 ; May 8, 1873 ; lat. 43° 2' N., long. 64° 2' W. ; depth, 51 fathoms ; 

 hard bottom. 



Boltenia legumen, Lesson. 



Bohemia legumen, Lesson, Centime Zoologique, p. 149, pi. liii. fig. 1 (1830). 



Boltenia coarcta, Gould, A. A., Mollusca, U. S. Explor. Exped. under C. Wilkes. Boston, 1852. 



(?) Boltenia legumen, Cunningham, the Nat. Hist, of the Straits of Magellan, Edin., 1871, 



pp. Ill and 263, and Notes on Eeptiles, &c, obtained during the voyage of H.M.S 



"Nassau," Trans. Linn. Soc., vol. xxvii. p. 489. 

 Boltenia legumen, Herdman, Prelim. Eep., Proc. Eoy. Soc. Edin., 1880-81, p. 81. 



The Boltenia coarcta of Gould is evidently the same species as Boltenia legumen, which 

 is figured by Lesson, and is an easily recognised species. Cunningham's figure (Straits of 

 Magellan) shows rather a different outline, but it is probably the same species. The Chal- 

 lenger specimens are of various sizes, ranging from 1*3 cm. to 7 cm. in length, and from 1'2 

 cm. to 3 "5 cm. in breadth. The shape of the body is ovate or ellipsoidal, and it is fixed by 

 a short, sometimes twisted peduncle attached to the ventral edge of the posterior end of the 

 body, and running downwards at right angles to the ventral edge, so that the body is 

 supported with the dorsal surface upwards, and the anterior and posterior ends on the 

 same horizontal plane. 



The apertures are both on the upper surface, but rather far apart, the branchial being 

 near the anterior end, and the atrial far back. Both are four-cleft, sessde, and very incon- 

 spicuous. The surface is very rough and covered with short bristle-like spines or hairs 

 which are sometimes branched. The specimen from Station 312 might be considered as 

 an echinated variety, as it has a dense coating of spines, which are usually much branched 

 and serrated. The colour varies from yellowish-brown through various ruddy shades to a 

 dark earthy brown. 



The test is thin but very tough and leathery. The inner surface is pale coloured. 



The mantle is moderately strong. 



The branchial sac has seven folds on each side. The internal longitudinal bars are 

 strong and numerous ; there are about eight on a fold and the same number in the inter- 

 space, where the meshes are elongated transversely and contain each about ten stigmata. 



The dorsal lamina is of no great breadth, but rather thick, so as to present the form of 

 a triangle in section. The edges are uneven but not toothed, and ribs are present along 

 the sides. 



The tentacles are branched and of different sizes. There are twelve or fourteen, large 

 and small alternately, with very minute ones placed here and there at the bases of the 

 larger ones. 



The dorsal tubercle, which lies in a small triangular peritubercular area, is large and 

 prominent, and has a circular outline. The aperture is small and is directed forwards. 

 Both horns are coiled inwards. The intestine forms a narrow loop. 



