EEPOE.T ON THE DEEP-SEA FISHES. 47 



and one-fourth in the total, without caudal It is very broad above, the width of the 

 interorbital space being two-fifths of the length of the head; eye rather small, one- 

 seventh of the length of the head in adult specimens, but comparatively larger in young 

 ones. Cleft of the mouth of moderate width, the maxillary extending to below the 

 middle of the eye ; jaws even in front. Nostrils small, close together, nearer to the end 

 of the snout than to the eye. Teeth minute, in a single series. Praeoperculum with 

 several small spinous processes on the margin. Bones of the head generally soft and 

 flexible. 



The upper profile rises abruptly from the interorbital space and describes a gentle 

 curve to the end of the dorsal fin. The anterior rays of the latter are short, but the 

 rays gradually increase in length backwards, those inserted on the posterior descending 

 part of the curve being the longest. Anal fin similar in shape to the opposite part of the 

 dorsal fin. Caudal fin rounded, with a semicircular base. Caudal peduncle with a 

 narrow fringe of the skin above and below. Pectoral broad, rounded, as long as the post- 

 orbital portion of the head ; ventrals much shorter, inserted immediately behind the 

 vertical from the base of the pectoral fin. Vent nearly in the middle of the length of 

 the body. 



The skin is naked, groups of minute spines indicate the course of the lateral line; 

 also the rays of all the fins are beset with minute spines. 



The gills are well developed ; the gill-rakers are thin, membranaceous, flexible papillae, 

 and as a broad membrane is stretched in the concavity of the arches, each l^ranchial 

 arch bears a series of gill-rakers inside as v,'ell as outside of the membrane. Pseudo- 

 branchise large, with a series of gill-rakers, similar to those of the branchial arches, along 

 the base. 



The fish is of a very light coloration, transparent below the dorsal and abo^■e the 

 anal ; its upper half is marked with large blackish spots, irregular in shape, smaller on 

 the head and neck than on the rest of the body ; they form a series along the base of the 

 vertical fins, which are similarly spotted. 



I have examined two specimens from California, of which one is 1 1 and the other 

 7 inches long. 



-"O" 



FamUy T r a c H i N i d.e. 

 Bathydraco. 



Batliydraco, Giintli., Ann. and Mag. Xal. Uist., 1878, vol. ii. p. 18. 



Body elongate, subcylindrical ; tail tapering and very attenuated behind; head 

 depressed, with the snout much -elongate, spatulate ; mouth wide, horizontal, with the 

 lower jaw prominent ; eyes very large, vertical, close together. Scales very small. 



