122 DEEP-SEA FISHES OF THE ATLANTIC BASIN. 



This species is known only from the Mediterranean, where it is very rare. The National 

 Museum has a specimen (No. 40054, U. S. N. 31.) from Nice, presented by the Royal Museum 

 at Floreuce, which corresponds perfectly to Gunther's description and figure, and also to 

 those of Risso and Valenciennes. Canestrini appears to have seen a dift'ereut type, which 

 he described as having the dorsal one-half as long as the anal, instead of one-third (D. 14; 

 A. 28). It is not impossible that this was another specific form. 



OMOSUDIS, Gunther. 



Omoeudis, GWnther, Challenger Report, xxn, 1887, 201. 



Body oblong, compressed, naked; head compressed; snout of moderate length; cleft of 

 month very wide; intermaxillary and maxillary bones slender, the former with a series of 

 very small teeth of equal size, only one or two anterior ones being somewhat enlarged; the 

 lower jaw, the vomer, and palatine bones with a few very large and lanceolate teeth. Lower 

 jaw broad, and, like the rest of the head, formed of very thin bone. The supraclavicle and 

 post clavicles form a long rod extending from the occiput on each side downwards to the 

 abdomen, and partly free, not covered by skin. Ventral fins inserted far behind the pecto- 

 rals, below the origin of the dorsal. Dorsal fin behind the middle of the length of the body; 

 adipose fin very small; anal fin long. Stomach very distensible. Branchiostegals, 8; pseu- 

 dobranchise well developed ; gills 4, with broad gill laminae and very short gill rakers. 



OMOSUDIS LOWII, Gunther. (Figure 150.) 

 Omosudis Lowii, GONTHER, Challenger Report, xxn, 201, pi. lii, figs, c, c". 



The length of the head is two sevenths of the total length (without caudal); the 

 greatest depth of the body immediately behind the head is one-fifth of the total length. The 

 head is strongly compressed, with rather flat upper surface ; snout somewhat pointed, rather 

 longer than the eye, the diameter of which is one-third of the length of the head. The 

 bones of the head are extremely thin, the operculum being smaller than the suboperculum, 

 and separated by two or three ridges. The infraorbital ring is nearly membranaceous. 

 Preoperculum terminating below in a forked point. Cleft of the mouth extending back- 

 wards to the angle of the preoperculum. 



The dentition is truly formidable for so small a fish; the longest tooth is one anteriorly 

 on the side of the mandible; in the British Museum specimens, only one is present either 

 on the right or left of the jaw; its length is nearly one-third of that of the head. The next 

 largest are those on the palate, where there are two on each side, besides several smaller 

 ones. Smaller teeth are also implanted on the hinder part of the dentary bone. All the 

 large teeth can be laid backwards. 



A semicircular scale like, osseous lamella of extreme, thinness covers the lower part 

 of the cheek, and is marked by very shallow, concentric striae. 



The singular bone which supports the side of the anterior part of the abdomen is 

 styliform, slightly curved backwards. It starts from the top of the occiput and descends 

 tow aids the median line of the abdomen, which it reaches behind the pectoral fin. It is 

 composed of the two pronged supraclavicle. which is fixed by ligaments to the occiput, and 

 of three slender, needle-shaped postclavicles; the uppermost postclavicle is suspended by 

 ligaments from the supraclavicle, as is also the clavicle. The rod lies immediately below 

 the thin integument, and its lower portion is quite free. 



The dorsal fin commences midway between the root of the caudal and the eye, and is 

 composed of very feeble rays ; the anal commences at some distance behind the dorsal and 

 terminates not very far from the caudal. Caudal fin small, with a considerable number of 

 basal rays above and below. Pectoral fins quite at the lower side of the body; ventral fins 

 very small and partly coalescent. 



Light brownish on the back, with numerous brown pigment spots on the sides; abdo- 

 men black. ( G ii n th er. ) 



