104 " ENDEAVOUR " SCIENTIFIC RESULTS. 



A second larger, but very badly stuffed specimen, is in the 

 Australian Museum, from Port Jackson. It is a male, and 

 agrees better with Ogilby's description than the specimen 

 figured. The spines and tubercles on the scapular region are 

 much more numerous, and are arranged in the quinque- 

 radiate formation described in the type ; the anterior pro- 

 jection extends forward almost to the level of the hinder 

 margins of the spiracles. The large tubercles on the median 

 line between the scapular region and the caudal spine, are 

 also more numerous than in the female figured. At some 

 distance behind the end of the spine the upper surface of 

 the tail is rough with small spiniform tubercles. 



The teeth of the male are triangular and acute, and the 

 outer surface of each is deeply grooved. In the female they 

 are tubercular with the surface broken up into numerous 

 small facets. 



Width of the specimen figured 271 mm. Length from tip 

 of snout to hinder margin of ventral fins 271 mm. Tail, from 

 posterior base of ventral fins 520 mm. 



Locs. Brisbane River, Queensland ; Port Jackson, New 

 South Wales. 



Key to the Australian species of Dasyatis. 



a. Tail with cutaneous folds sub-genus DASYATIS. 



b. Tail with a small fold above as well as below. 



c. Scapular region smooth, or with spines on median line 



only ; upper surface with blue spots kuhlii. 



cc. Scapular region with a broad patch of tubercles ; 



upper surface uniformly coloured ftuviorum. 



bb. Tail with a fold below, none above. 



d. Back smooth or with isolated tubercles 



brevicaudatus. 



dd. Back with numerous tubercles thetidis. 



aa. Tail without cutaneous folds. . . .sub-genus HIMANTURA. 

 e. Back smooth in the young, tubercular in adults . uarnak. 



Family MYCTOPHID^E. 

 Genus ELECTRONA, Goode & Bean. 

 ELECTRONA RISSOI, Cocco. 



Scopelus rissoi, Cocco, Giorn. Sicil., fasc. 77, p. 144, fide 

 Gunther, Brit. Mus. Cat. Fish., v., 1864, p. 405. Id., 

 Collett, Res. Camp. Sci. Monaco, x., 1896, p. 113. 



Myctophum rissoi, Chun, Wiss. Ergebn. " Valdivia," xv., 

 1906, p. 170, fig. 83. 



Electrona rissoi, Goode & Bean, Oceanic Ichth., 1895, p. 

 91, pi. xxviii., fig. 107. 



