REPORT ON A COLLECTION OP AMPHIOXUS. 361 



Report on a Collection of Amphioxus made 

 by Professor A. C. Haddon in Torres Straits, 

 1888-9. 



By 



Ai'thui' IViUey, B.Sc.L.oud. 



This collection^ comprising some ninety specimens of Am- 

 phioxus, was obtained by Professor Haddon between the months 

 of September, 1888, and January, 1889, inclusive, and was 

 placed by him in the hands of Professor Lankester, who kindly 

 entrusted it to me for examination. 



The specimens were in a good state of preservation, and a 

 careful study of them has revealed several facts of interest. 



They were taken from different localities (Flinder's Entrance, 

 Mabinag, &c.), at depths varying from six to thirty fathoms, 

 the sea bottom being here, according to Professor Haddou's 

 records, largely composed of fine broken shells. 



They all belong to one species of Branchiostoma,^ namely, 

 B. cultellum = Epigonichthys cultellus, Peters. 



This species can be distinguished at a glance by the great 

 development of the dorsal fin, which presents a striking appear- 

 ance on account of the unusual height to which it projects 

 above the body. The height of the fin gradually increases 

 from behind forwards, reaching its climax in front in the 

 region of the seventh and eighth myotomes. The distinctive 



1 As it is not only out of the question, but undesirable, to relinquish the 

 name "Amphioxus," although " Branchiostoma " has the priority, the 

 latter, followiug the precedent set by Giinther, is retained as the systematic 

 name of the genus, while the former may be regarded rather as a colloquial 

 name. 



