122 DEEP-SEA PISHES OF THE ATLANTIC BASIN. 



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

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

 at Florence, which corresponds perfectly to Giinther's description and figure, and also to 

 those of Risso and Valenciennes. Canestriui appears to liave seen a dilfereiit 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, Gunlher. 



Omosudis, GCnther, Challenger Report, xxii, 1887, 201. 



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

 mouth 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 beiug somewhat enlarged; the 

 lower jaw, the vomer, and jialatine 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 supraclavide and 

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

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

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

 adipose flu 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, GCnther. (Figure 150.) 

 Omotudis Loioii, GOnther, Challenger Eeport, xxii, 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 sc-\'eral smaller 

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

 large teeth can be laid baclcwards. 



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

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



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 

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

 composed of the two i)rongpd supraclavide, which is fixed by ligaments to the occii)ut, and 

 of three slender, needle-sliaped postclavicles ; the upi)crmost postclavicle is suspended by 

 ligaments from the supraclavide, 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 (juite at the lowei' 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. (GUnthcr.) 



