346 CEYLON PEARL OYSTER REPORT. 



to the margin and on the outer side bear three short branches projecting at right 

 angles and nearly reaching to the margin. The innermost prong of the fork is shorter 

 than the 2 outer and bears 3 white tubercles. A very slight alteration of the white 

 bands in P. nobilis, as figured by BERGH, would produce the pattern here described. 

 It may be, however, that it should be referred to the variety of P. varicosa figured 

 by BERGH (9, plate xxv., fig. 7). The underside of the Ceylon specimen is of 

 a pale bluish-grey with 3 to 4 lateral ill-defined black spots. 



(DORIDID.E PHANEROBRANCHIAT.E.) 

 SUB-FAMILY : POLYCERIN^. 



Aegires villosus, n. sp. Plate III., figs. 18 to 22. 



One specimen (Plate III., fig. 18) of the above, length 0'9 ceritim., was taken to the 

 north-west of Cheval Paar. The body is elevated, with a medio-dorsal bunch of long 

 clavate processes or elongated tubercles (Plate III., fig. 19) surrounding the branchial 

 pore ; two of these processes are slightly branched. There are two irregular lateral 

 lines of slightly clavate tubercles on each side of the body, and small tubercles are 

 crowded on the nape of the neck. There are longitudinal patches of purplish -brown 

 pigment lying between the tubercles on the back and sides. The ends of the tubercles 

 are shaded with brown. The ground colour is a dirty greyish-white. The surface of 

 the body and tubercles is densely spiculose, the spicules projecting and giving the 

 animal under slight magnification a densely pilose appearance. 



Rhinophore sheaths (Plate III., fig. 20) with 3 outer moderately long tubercles, 

 and 1 small inner tubercle. The radula shows that the specimen is evidently 

 immature, it contains only 12 rows with 16 simply hooked teeth (Plate III., fig. 22) 

 on each side. The jaws are not developed, but the chitinous collar shows slight 

 lateral thickenings and a well-marked upper jaw (Plate III., fig. 21). 



This genus has previously been known only from the Atlantic and Mediterranean. 



Trevelyana bicolor, ALD. and HANC. 



One specimen of what appears to be this species was found on Galle coral reefs in 

 August, 1902 ; length, 1'2 centims. The colour has been lost and the skin is trans- 

 parent, showing the internal organs. The liver occupies the posterior two-thirds ot 

 the body and is of a bluish-grey colour. The branchiae are 12 in number arranged in 

 a circle round the anus on the centre of the back. The area of skin surrounding the 

 branchiae is more opaque than elsewhere, which seems to suggest that it is of a 

 different colour during life. There is a branching white arrangement, probably 

 vascular, anteriorly on the surface of both sides of the body. The rhinophores are 

 retracted. The size and number of branchiae of this specimen seem to point to its 

 being T. bicolor. The radula was not examined. 



