OPISTHOBRANCHIATE MOLLUSCA. 339 



The number of lateral teeth on each side is 48, the 6 or 7 outermost being fringed 

 instead of simply hooked. The penis seems to have been armed as in Platydoris 

 with hooked plates, but the preparation was unfortunately mislaid before examination. 

 The vagina (Plate II. , figs. 22 and 23) is very strongly armed with two longitudinal 

 rows of peltate discs, very convex, the boss formed of a single powerful spine ; there 

 are about 16 discs on each side opposite each other, but not arranged in pairs. They 

 are largest in the centre of the rows and become much smaller towards each end. 



The stomach (Plate II., fig. 21) is of an unusual structure, the intestine leaving it 

 medio-dorsally instead of anteriorly, as is usual. The radula sac is long and curved 

 upwards on the left side of the oesophagus (Plate II., fig. 20). 



This species differs from the usual type of Platydoris in the long radula sac, form 

 of the radula, structure of stomach and larger size of dorsal tubercles. It agrees 

 with it in its general flattened form and genital armature. It is probable that an 

 examination of further specimens will make it clear that a generic distinction exists. 



SUB-FAMILY: DIAULULIN^E. 

 Halgerda punctata, n. sp. Plate III., figs. 4 to 7. 



There are in the collection (Gulf of Manaar) two specimens of a moderately large 

 glabrous Dorid with the mantle raised into tubercles, more or less connected by 

 ridges, for which I propose the above name. I have placed it in the genus Halgerda, 

 as it agrees in most points with the single known species Halgerda fovnwsa. 

 Professor HERDMAN'S notes describe what must be this species as follows : " Dorid, 

 W. of DONNAN'S Paar, 29 faths., March llth, 1902; pale whitish-grey, rather 

 translucent, with yellow papillae on mantle, and purple spots on foot and a few also 

 on mantle." 



The ground colour of both the preserved specimens is white on both sides of the 

 mantle, and on the foot. The mantle is flecked with a few black spots, which 

 measure from 0'5 millirn. to 1'5 millims. in diameter, appearing to be of tougher 

 consistency than the rest of the body, and to extend to a slight depth. In one 

 specimen there are only four such spots, very small, near the posterior end, but in the 

 other they are more numerous, about twenty, arranged more or less symmetrically. 

 There is a pinkish tinge on the apices of some of the tubercles. The under-side of 

 the body of both specimens is marked with black spots similar to those found on the 

 notseum, but more numerous, especially on the specimen which is more spotted above. 

 The size is about the same in both specimens : length about 3 centims., width 

 2'8 centims., height 1'5 centims. The mantle is glabrous, moderately tough, and 

 bears numerous large blunt'tubercles arranged in more or less diagonal lines connected 

 by ridges which form an irregular triangular network. This arrangement is much 

 more distinct in one specimen (figured on Plate III., fig. 4) than in the other, which 

 has much fewer tubercles, and in which the ridges are almost obsolete. The branchial 



2x2 



