SIK CHARLES ELIOT. 



T. belli appears to have two renal orifices situated close together. The second is 

 possibly analogous to the pore of unknown functions in Hexahranclms (v. Bergh in 

 Semper's Reisen, XVIII. , p. 551, under II. faustus). In T. simiata the orifices were 

 contracted and their character could not be precisely determined. 



2. — Tritoniella belli (Figs. A * and B). 



The collection contains five specimens of this form, which present considerable 

 differences in shape and in the greater or less development of the mantle margin and 

 the processes which it bears. Mr. Hodgson, however, informs me that they all 

 appeared to him to be the same species when captured, and were all milk-white. This 

 and the identity of the internal anatomy cause me to describe them as one species and 

 not to distinguish even varieties, since the diversity of appearance, though considerable, 

 is probably due to artificial causes. The animals have no doubt the power of altering 

 their shape from flat and broad to high and narrow, and the Tritoniidse are very apt to 

 have their mantle margin and branchife rubbed off, without any clear sign of the loss 

 remaining. Besides being exposed to ordinary distortion, the present specimens were 

 captured in a temperature which caused them to freeze into solid lumps before they 

 could be placed in the preserving fluid. 



The specimens may be classified as follows : — 



A. One specimen captured at Hut Point, Winter Quarters, February 13, 1904, 

 with the D net. It appears to be very well preserved, and is of a uniform pale yellow. 

 Length 50mm., maximum breadth 30, height 19. The l)road undulated mantle-edge 

 bears a row of papillae, and the oral veil is distinctly tuberculate. 



B. Two specimens from McMurdo Bay, 4-10 fathoms, February 13, 1902, and one 

 specimen captured with the D net at Winter Quarters, hole No. 12, on August 24, 1903. 

 In all these specimens the edges of the mantle and of the oral veil are much less distinct 

 than in A, and there are only a few processes. The measurements are as follows in 

 millimetres. 



One of these specimens is represented in Figs. 1 and 2. 



C. — One specimen captured with the D net at Hut Point, Winter Quarters, 

 November 19, 1902. Colour, grey ; back much arched ; anterior portion, especially 

 left rhinophore, greatly swollen. This specimen, which is superficially unlike all the 

 others, appears to have sufiered considerable distortion, which is confirmed by the fact 

 that the viscera have been drawn up into the anterior part of the body cavity, leaving 

 the posterior half empty. 



* The letters refer to figures on the plate ; the text figures are distinguished by cyphers. 



