1906,] OF SOUTHERN INDIA AND CEYLON. 68S 



LiNGUELLA SARASINICA Bei'gh. 



(Bergli, " Weitere Beitr, zur Kennt. der Pleiiroph.," Verli. 

 k.-k. zool.-bot. Gesells. Wien, 1890, pp. 10-12. Eliot, 

 " Nudibr. from the Indo- Pacific," J. of Ooncli. ii. 8, 1905, 

 pp. 240-1.) 



A single specimen, which looks well-preserved but is very soft 

 and crumbly. It is broad and flat, but rolled up. If stretched 

 out, it would be about 60 mm. long and 40 wide. The colour is 

 yellowish grey of various shades, with a white border round the 

 mantle. The back is covered with tubercles of various sizes. The 

 smaller are mostly pointed. The larger are flat roundish plates, 

 as much as 2*5 mm. broad, and showing signs of a central peak 

 which has perhaps been flattened by artificial pressure. 



At first sight the conformation of the anterior part seems to be 

 as in Pleu7-ophyllidia, the mantle-margin being continuous behind 

 the rhinophoi'es. But the white border is interrupted, and a 

 careful examination proves that the apparently continuous fold is 

 due to contraction, and that the dorsal surface is prolonged un- 

 interruptedly between and before the rhinophores. The surface 

 in front of the rhinophores is studded with conical papUlse and 

 flat tubercles like those of the back but rather smaller. The giUs 

 lie between the body and the mantle-edge, not in a cleft. They 

 are only 30-40 in number, thin and of vaiying size, the largest 

 being 7 mm. The side-lamellse are much larger and thicker than 

 the gills, but are not numerous (20-30). They are often inter- 

 rupted a,nd broken, so that it is hard to count them. The tail is 

 short, and there is a deep furrow in the posterior part of the foot. 



The yellow jaws are large, each being about 1 1 mm. long and 

 5 mm. broad. The middle part is very convex. The edge bears 

 minute irregular lumps, but is not denticulate. On the inside of 

 the masticatoiy process is a triangular membranous flap about 

 2 mm. long. The radula consists of 55 rows containing 120-130 

 teeth on each side of the rhachis. The rhachidian tooth is not 

 very wide but arched, with a deep sinus behind. The central 

 cusp is moderately prominent, and bears 2-3 denticles on its 

 slope ; below them are about 8 ridges terminating in denticles on 

 either side of the tooth. The first lateral is hardly hamate, but 

 squarish with a iew (generally 4) denticles. The remaining teeth 

 are hamate. The second and third bear 8-12 denticles. Then 

 the number of denticles decreases, and after about five teeth the 

 appearance is bifid, though accessory denticles beneath the bifur- 

 cation occur throughout the row. In general, the denticulation 

 is irregular. Smooth teeth occur here and there throughout the 

 outer half of the row, and the last ten are usually, though not 

 invariably, smooth. 



I think this form may be referred to L. sarasinica, recorded 

 from Trincomalee and the Persian Gulf. The jaws, however, 

 present differences, and are not denticulate as in the specimens 

 previously examined. But the denticulations may wear ofiE" in the 

 larger and older individuals. 



