10 SIR CHARLES ELIOT. 



than 7 mm. wide. lu the upper part are soft lamelhe and papillte, and iu the lower a 

 rin" of fifteen to twenty hard ridges, which look like the stomach plates of Marionia, 

 but are not detachable. The circuit of plates is broken by the large liver duct which 

 enters the stomach at about this point. The hinder part, but not the whole, of 

 the stomach is enclosed in the greyish liver mass, which is itself covered here 

 and there, but by no means everywhere, by a thick reddish layer consisting of the 

 follicles of the hermaphrodite gland. The intestine is laminated internally. It 

 issues from the middle of the liver mass, runs a long way forward, and then turns 

 backward and to the right. In one specimen fragments of shells were found in the 

 digestive organs. 



The ampulla of the hermaphrodite gland is long (about 25 mm. x 4 mm., if 

 straightened out), and folded about four times on itself. The vas deferens is 

 reddish yellow, and lies in a few large, loose coils (about 40 mm. x 1 • 5 mm., if 

 straightened out). The verge is rather small, conical, and pointed. The mucous 

 and albumen glands are not large in any of the specimens, and it is probable 

 that the animals were not captured in the breeding season. The spermatotheca 

 has a short duct ("2 -5 mm.), and is elongate (about 8 mm. x 2 mm.), with 

 strong, muscular walls. In all the specimens it is contracted and twisted in the 

 middle. The external orifices of the reproductive organs are protected by folds of 

 moderate size. 



The renal orifice, which lies immediately in front of the vent, is remarkably 

 distinct in all the specimens ; and in most of them it can be seen that it consists 

 of two openings, very close together, the anterior smaller than the posterior. Both 

 appear to communicate with the renal apparatus, but the connection was not 

 satisfactorily discovered. Attached to the intestine is the reddish, egg-shaped, renal 

 vesicle, lined with branchia-like lamellae. 



3. Tritoniella sinuata (Fig. C). 



One specimen, captured at Winter Quarters on October 8, 1903, with the 

 D net in hole 12 (25-30 fathoms). It is of a uniform, light-yellow colour, and 

 well preserved, but swollen ventrally, which is probably unnatural. It is narrower 

 and higher than the specimen of T. belli, the measurements being : length, 30 mm. ; 

 breadth, 10*5 ; height, 12. 



The dorsal margin rises vertically, not laterally, about 5 mm., and bears on each 

 side 30 points, which are continued below into low ridges, running towards the 

 centre of the back, but not reaching the central ridge. It is not clear if these 

 transverse ridges are permanent, or mere folds produced by contraction. Three 

 of the points are larger than the others, and measure 4 mm., including the ridges; 

 five are of moderate size (3 mm., including the ridges), and the rest are small. On 

 the under side of the points are a few indistinct lamellfe. 



The oral veil is bi- or trilobed, as the central portion is somewhat expanded 



