OPISTHOBRANCHIATE MOLLUSCA. 355 



being simply hooked (Plate V., fig. 17), while towards the margin the hook becomes a 

 long scythe-shaped blade (Plate V., fig. 16). 



Notarchus indicus, SCHWEIG. 



I have, on account of the resemblance of the radula to the figures given by BERGH 

 (11, plate vii.), referred to this species 20 little immature specimens of Notarchus, 

 from Ceylon. The largest of these measured 1*2 centims. in length. The label 

 indicating the exact locality where they had been taken has unfortunately been lost. 



Notarchus ceylonicus, n. sp. Plate V., figs. 18 to 23. 



There is in the collection one specimen of Notarchus, from ^ mile east of Dutch 

 Modragam Paar, for which I propose the above name. 



The form of the body (Plate V., fig. 18) is ovate, very plump, and inflated, except 

 as regards the head. The foot is moderately wide and pointed behind. There is no 

 shell. The branchial slit is short, length 6 millims. The length of the animal is 

 3 '3 centims., width 2'1 centims., height 1'6 centims., width of foot I'l centims. 



The surface of the body and head bears numerous small fringed papillae which 

 occur more thickly on the head, probably owing to its contraction. The rhinophores 

 and tentacles are fringed with similar papillae. Very small labial processes are 

 present. 



The radula (Plate V., figs. 20 to 23) consists of 30 rows of 33-1-33 teeth, the first 

 8 rows being imperfect. The first 5 teeth from the centre have four lateral denticles 

 on the outer edge, the following 9 three denticles, the basal denticle being small and 

 blunt, and becoming hard to recognise at a little distance from the centre. The next 

 4 teeth have two lateral denticles. From the 18th to the 24th tooth the distal 

 denticle only persists, and the 9 outermost teeth are smooth and scythe-shaped, thus 

 differing from those in N, indicus, which are serrulate. 



FAMILY : PLEUEOBRANCHID^. 



Pleurobranchsea brocki, BGH. -Plate V., figs. 24 to 28. 



It is with some doubt that I refer to this species a well preserved specimen ot 

 Pleurobranchtfa, which was taken 5 miles north of Cheval Paar in March, 1902. 



The colour of the preserved specimen is an opaque brownish-yellow, due evidently 

 to its preservation in spirit. On the mantle and upper surface of the hinder parts 

 of the foot there are rusty-brown markings in coarse irregular reticulations, occupy- 

 ing to some extent the furrows on the mantle. 



The form of the body (Plate V., figs. 24 and 25) approaches the Mediterranean 

 species P. meckelii. The total length is 3'2 centims., width (of foot) 1*7 centims., 

 height I'l centims., length of mantle 2 '6 centims., width 1'5 centims., length of foot 

 behind body 07 centim., length of gill from genital papilla 1'2 centims., height of 

 caudal papilla 3 '5 millims. 



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