CLASSIFICATION OF THE CEPHALOCHOEDA. 289 



found in 35 out of 58 specimens-. In B. belcheri from 

 Ceylon the total varied between 63 and 66, the average 

 being 64 found in 31 out of 55 specimens. The commonest 

 myotome formula for B. nakagawce was 36, 17, 11, or 37, 

 17, 10, the former was observed 16, and the latter 11 

 times out of 58 specimens. In B. belcheri from Ceylon 

 I found the commonest formula to be 37 (38), 17, 9, which 

 occurred 28 times out of the best 55 specimens. 



It is, therefore, evident that the closest affinity exists 

 between the two species, as our Ceylon collection shows. 

 In size, in number of buccal cirri, in the range of myo- 

 tomes, and in the average number of myotomes, they agree 

 exactly. The commonest formula? of both are very close 

 indeed. It must be admitted, then, that B. nakagawce 

 is really the same as B. belcheri, which, as I have 

 endeavoured to prove, is merely a variety of B. lanceolatum. 

 I append a detailed comparison of the two in tabular 

 form. 



The species of the genus Asymmetron are all well marked, 

 with the exception of A.-caudatum. There is nothing to 

 say about A. cingalense, A. cultellum and A. bassanum. 

 They are all three well characterised species. 



A. hectori has only 4-6 more myotomes than A. bas- 

 sanum. It is only known from two specimens, and 

 although only differing in this respect from A. bassanum, 

 it is well at present to keep it distinct. Its formula is 

 53, 19, 12. A. maldivense is a new species lately found 

 near the Maldives during Mr. Stanley Gardiner's expe- 

 dition. In general shape, and in the shape of the fins, 

 it is remarkably like A. cultellum. Especially is this so 

 with the dorsal fin, which is much swollen anteriorly as 

 in A. cultellum. In the number of gonads and myotomes 

 it agrees more closely with A. bassanum. It has 73 

 myotomes arranged 45, 16, 12, which is not unlike the 



