348 CEYLON PEARL OYSTER REPORT. 



Family : PHILINIDiE. 



Philine aperta, Linn. Plate IV., fig. 1. 



This is one of the most abundant species in the collection. It is represented from 

 the Gulf of Manaar, Galle, deep water off Galle, Trincomalee, off Kaltura, the 

 pearl banks off Aripu, and south of Modragam in all 42 specimens, of which 

 33 came from the Gulf of Manaar. The specimens vary considerably in appearance 

 owino- to their different degrees of contraction, but the shells are identical in texture 

 and almost so in shape. The shells (Plate IV., fig. 1) are of a moderately elongated 

 oval form with a smooth somewhat opalescent surface, and agree with P. angasi, 

 from Australia ; but I do not think that the slight difference in form between these 

 shells and those of British specimens of P. aperta can be regarded as amounting to 

 a sjDecific distinction. There was no constant difference to be noted between the 

 gizzard plates and those of the typical P. aperta, though in most cases the ventral 

 plate was more asymmetrical and the ends of the lateral plates more produced. 



The radula was as in P. aperta. 



Bergh (12) has recorded P. aperta as occurring not uncommonly in the Gulf of 

 Siam, and it seems not improbable that it has a cosmopolitan distribution, and is 

 represented by local races in many places ; as such perhaps may be : P. vaillanti, 

 P. erythrcea (though that species is said to be distinguished by the peculiar serration 

 of its gizzard plates), P. angasi, P. orientalis, P. caurina, P. vitrea and P. coreanica. 



Doridium marmoratum, Smith. 



One specimen from the Gulf of Manaar should, I think, be referred to D. mar- 

 moratum. Its length is 2 - 2 centims., width 1"1 centims. ; length of head shield 

 1'3 centims., width 1"1 centims. The ground colour is a dark brownish plum with 

 numerous small pale oval or circular spots, those on the foot being rather larger than 

 those on the rest of the body. The margins of the foot and the front margin of the 

 head shield are marked with a bluish-black line. The sole of the foot is slightly 

 darker than the rest of the body. The lateral margins of the foot are closely 

 adpressed to the sides of the animal. The head shield appears to be emarginate 

 posteriorly, owing to its posterior extremity being turned up. The gill protrudes 

 through the mantle slit on the posterior end of the body, probably owing to an 

 injury, as the specimen is in rather bad condition, the pharynx having been everted 

 through a rupture in the front of the head shield and the shell crushed to fragments. 

 D. marmoratum has only been recorded from Torres Straits (7). 



Doridium depictum (Ren.), var. 



A small specimen dredged on Periya Paar, in 9 fathoms, had the following colora- 

 tion, as noted by Professor Herdman, while alive, " brown, mottled with pale green, 

 and having two yellow lines from the head backwards ; front edge of foot blue, lobe 



