BATHYDORI8. 17 



5. BATHYDORIS INFLATA (FiG. D). 



ONE specimen, labelled W.Q. Feb. 1902. The distended egg-shaped body projects 

 considerably over the head in front so that the length dorsally is 17 mm., whereas the 

 length from the mouth, which is ventral, to the tip of the tail is only 13 mm. The 

 breadth is 12 5 mm. and the height 11 5 mm. The colour is dark chocolate of various 

 shades, the internal organs being visible through the skin as in the last species. The 

 rhinophores, tentacles, branchiae, foot and marginal papillae are yellow. The few 

 remaining dorsal papillae are whitish. 



The foot is 9 mm. broad and only 10 mm. long. It is grooved in the same way as 

 the last species and has a projecting lateral margin about 3 mm. wide. The tail is short. 



The dorsal and marginal papillae are much as in the last species, but there is no 

 reticulate pattern. They are sparsely scattered over the back, there being only about 

 twenty facets on the dorsal area visible from above. They are most numerous near 

 the margin, especially over the head, where they form a sort of oral veil. Most of 

 them are irregular in shape with various bulges and wrinkles, but a few near the 

 rhinophores are straight and as much as 4 mm. long. 



The mouth is open and bears on each side a pointed conical tentacle, which is 

 deeply grooved near the base and about 3 5 mm. long. 



The rhinophores are straight, 3 ' 5 mm. long, and bear about twenty distinct 

 perfoliations. There is no trace of a pocket. 



The branchiae are five or six in number, according as the anterior group, which 

 consists of two plumes close together, is counted as one or two. The rest are single, 

 and not tufts composed of several plumes. They are tripinnate but minute, being not 

 more than 1 mm. broad, and easily detachable. Within the branchial circuit is a 

 small sub-central renal opening. Behind is the anus, which is not very prominent. 



The interior of the animal is almost entirely filled with a solid mass composed of 

 fragments (some as large as 8 mm. by 7 mm.) of a semi-transparent, reddish-brown 

 substance, resembling horn or hardened glue. The state of the ossophagus, which is 

 lined with this substance, suggests that the animal must have distended itself by 

 swallowing some kind of jelly which, under the action of the preserving fluid, hardened 

 into an almost vitreous mass. The colour of the integuments is due to this substance, 

 and, when removed, they are transparent and very brittle. Most of the internal 

 organs have been distorted and hardened out of all recognition. Besides the buccal 

 mass can be distinguished only the outline of the fern-like kidney and of the intestine, 

 which are compressed against the dorsal wall, and some hard fragments of the 

 oesophagus, liver, hermaphrodite and mucous glands. 



The jaws lie in the fore part of the buccal mass, and form a disc about 3 mm. in 

 diameter, covered by strong membranes, which are pierced by an aperture 7 mm. wide. 

 In structure they resemble the jaws of the last species. The radula consists of twenty- 

 two rows, and the teeth are deep yellowish brown. They increase regularly in number 



