OPISTHOBRANCHIATE MOLLUSCA. 353 



Aplysiella mollis, a. sp. Plate IV., figs. 22 to 26 ; PI. V., figs. 2, 3 ; PI. VI., fig. 1 1. 



There arc two specimens from South Cheval Paar. 



The length of the larger specimen is 2"4 centims., width T2 centims., width of 

 foot 1 -.3 centims., height I/O centim., length of branchial slit l - centim., front of 

 head to commencement of branchial slit 1*2 centims. 



The colour of the preserved specimens is white, semi-opatpie. They are of soft, 

 wrinkled, and of a somewhat flabby consistency. 



The animal (Plate VI., fig. 11) is moderately swollen, Aplysia-like in form, with 

 short branchial slit. Over the surface of the back are scattered small spiky papilke, 

 much fewer in one specimen than in the other. The rhinophores are moderately long, 

 of the usual form. The tentacles are short, split as usual, and flattened. There is a 

 slight development of labial flaps. The eyes are distinctly visible. 



The shell (Plate V., figs. 2 and 3) is shaped as in Aplysia. It is membranous, with 

 a very brittle, opaque white calcareous layer covered with small nodules. 



The radula (Plate IV, figs. 22 and 24 to 26) consists of 33 rows of 48-1-48 teeth, 

 the inner cusp being the larger in the 1st to 4th tooth from the centre and the 

 outer cusp the larger from the 5th tooth outwards. The outermost 5 or 6 teeth are 

 narrow, curved, and simple. The labial armature (Plate IV, fig. 23) is made up of 

 rods, bent and bifid at the tips. 



Dolabrifera maillardi, Desh. Plate V., figs. 4 to 10. 



One specimen from Muttuvaratu Paar, 8 fathoms, March 1902. 



The original species of Deshayes was only described from the shell which came 

 from Reunion (5). His description and figure agree fairly accurately with the shell 

 of the Ceylon sjiecimen. The preserved specimen (Plate V., figs. 4 and 5) is smooth, 

 somewhat plump, moderately elongate, of a dirty white colour. Its length is 

 l - 9 centims., width T3 centims., height 0'9 centim. Professor Herdman's notes 

 contain a sketch of the living animal and state, " Port-wine colour, with a limited 

 number of white spots having each a spiky papilla rising from its centre." 



The foot is as broad as the body, with its margins slightly frilled. It does not 

 extend beyond the body posteriorly. The body is elevated posteriorly and slopes 

 forward somewhat, as in Dolahella. The branchial slit is short and narrow, length 

 0"6 centim. It commences at about the posterior third of the body and runs 

 hackwards. The tentacles and rhinophores are tubular and slit externally. 



The radula (Plate V., figs. 6, 7, and 10) consists of 35 rows of about 62-1-62 teeth. 

 The median tooth has a central cusp, and two lateral cusps on each side. The innermost 

 teeth of the lateral rows have two large hooked cusps, and a small basal cusp on the 

 outer side. This basal cusp is found on about the 20 innermost teeth, after which it 

 disappears. The outermost teeth are long, slender, and bifid at the tips. 



The shell (Plate V., figs. 8 and 9), length 4"6 millims., has an embryonic spine just 

 below the apex, the apex itself being formed by a flattened plate or callus. 



2 z 



