Dr. E. F. Kelaart on a new Ceylonese Nudibranch, 257 



Fig. 2. I. gracilis; magnified 4 times: a, right valve; b, anterior view, 

 and c, ventral; d, magnified portion of the marginal rim. From 

 AVliite Horse Rapids. 



[From Pauquette's Rapids. In the Museum of the Geol. Survey of Canada.] 

 Fig. 3. Cytheropsis concinna ; left valve ; magnified 12 times. 

 Fig. 4. C. concinna; ventral aspect of the closed valves; magn. 12 times. 

 Fig. 5. C. rugosa; magnified 12 times : a, right valve; b, ventral aspect 



of the closed valves ; c, portion of the surface, magnified 50 



times. 

 Fig. 6. C. Siliqua; right valve; magnified 12 times. 



Fig, 7. Leper ditia gibber a, var. scalaris : a, internal cast of the left valve; 

 b, ocular and muscular spots, magnified. From Williamsville. 

 In the Museum of the Geological Society. 



[From Pennsylvania.] 

 Fig. 8. L, alta : right valve, natural size. 

 Fig. 9. L. alta ; internal cast of left valve ; natural size. 



[From Schoharie. In the Museum of the Geological Society.] 



Fig. 10 a. L. gibber a, xdx. scalaris; left valve; natural size; 6, ocular and 



muscular spots, magnified. 

 Fig. ILL. gibbera, var. scalaris; right valve; natural size. 



[From Pennsylvania.] 

 Fig. 12. L. Pennsylvanica : «, right valve, natural size ; 6, ocular and 



muscular spots, magnified. 

 Fig.\3. L. Pennsylvanica; left valve; natural size. 

 Fig. 14. L. ovata ; right valve ; natural size. 

 Fig. 15. B. Maccoyiana : a, left valve, magnified 4 times; b, portion of 



surface, highly magnified. 

 Fig. 1 6. jB. Pennsylvanica, right valve ; magnified 4 times. 

 Figs. 17, 18 a. B. Pennsylvanica, left valves; magnified 4 times. 

 Fig. 18 6. B. Pennsylvanica; portion of the surface, highly magnified. 



XXII. — Description of a new Ceylonese Nudibranch. 

 By Br. E. F. Kelaart. 



[With a Plate.] 



Doridse. 



Trevelyana, new genus. 



Body without a cloak. Two dorsal tentacles, without sheaths ; 

 non-retractile. Mouth in front of head, without tentacles. 

 Branchiae in a circular disk on the back, non-retractile. 



Trevelyana Ceylonica. (PL X. B.) 



Body If inch long, narrow, elevated and inflated near the bran- 

 chial plumes ; semigelatinous, white, and spotted with small 

 Ann. ^ Mag. N. Hist. Ser. 3. Vol i. 17 



