DISCUSSION OF SPECIES AND THEIR DISTRIBUTION. 205 



Lepidopus. Top of head very flat, concave between the eyes, with no occipital crest. luter- 

 orbital ridges not elevated. Eyes large, slightly postinedian. Operculum oblong, reaching 

 a little beyond the base of the pectoral flu. Nostrils horizontal, in front of the eyes. 

 Supramaxillary not extending to vertical from front of eyes. Lower jaw with stout cutane- 

 ous ai)pendage. 



Three very long, simple, compressed teeth on each intermaxillary in front; outside of 

 these a few minute teeth, and behind them a row of large acicular teeth. In lower jaw a 

 single row of moderately large acicular teeth, more numerous than in the upper jaw, largest 

 in the middle of the jaw. I'alatine teeth minute. 



Dorsal fin, beginning above the operculum, nearly uniform in height throughout its 

 entire length, and continuous almost to the caudal. Bays very numerous (over 150 in B. 

 clomjatuii). Anal beginning near the vent, preceded by a single scale-like appendage; 

 si)ines very numerous (numbering with the rays about 100 in B. clongatus, all excejit 28 or 30 

 being spines), minute and almost hidden; a short fin posteriorly. 



Caudal small, normal, forked. Pectoral inserted almost horizontally, with lower rays 

 longest, and its upper outline rounded. Ventral fins represented each by a minute scale- 

 like spine, inserted below the origin of the pectorals. 



Pseudobranchiae present; gills 4, a slit behind the fourth. Gill-rakers short and spiny, 

 in a single series on the first and second arches, almost obsolete on the third and fourth. 

 (In Lepidopus caudatus all the arches are supplied with several series of rakers.) 



Benthodcsntiis may be distinguished from Lepidopus and Evoxymetopon by the following 

 salient characters: 



1. The slenderer, lower form of the body, the height of which in B. elongatus at the 

 vent is one-fourth the length of the head; in Lepidopus caudatus, nearly half the length of 

 the head. 



2. In the location of the vent, which is considerably nearer to the head. 



3. In the depressed form of the head, its fiat profile, the insignificance of the frontal 

 ridges, and the absence of the occipital crest. 



4. In the much greater number of dorsal rays. 



5. In the more advanced position of the rudimentary ventrals, which are situated in 

 Benthodesmus under the base of the pectorals. 



G. In the presence of a single small postanal scute, in place of the two larger ones in 

 Lepido2)us. 



10. In the characteristic arrangement of the gill-rakers. 



BENTHODESMUS ATLANTICUS, Goode aud Bean, n. s. (Figure 215.) 



Benthodesmus elongatus, Goode and Bean, Proc. U. S. Nat. Mus., iv, 1881, 380-3, Figure. — Jordan and Gu.- 

 BERT, Bull. XVI, U. S. Nat. Mus., 1883, 910.— Jordan, Cat. Fish. N. A., 1885, 67. 



Body attenuate, its height at the vent contained four times in length of head, its width 

 being about one-third of its height at the point mentioned. Length of caudal peduncle 

 half of greatest height of body. Least height of tail one-third ^\idth of interorbital area. 



Length of head contained seven and a half tinu'S in length of body, its greatest width 

 one-sixth of its length; its greatest height nearly one-fourth of its length; width of interor- 

 bital area (on the bone) one fourth of the height of the head. Length of snout contained 

 2J times in length of head. Upper jaw not reaching to vertical from anterior margin of 

 eye, and equal in length to the postorbital jwrtion of head. Lower jaw in length equal to 

 about twice the greatest height of body. Mandibular tip nearly one-third as long as the 

 diameter of the eye. Eye slightly postmedian in location, the orbital diameter equal to half 

 the length of the snout. 



Besides the three long teeth, there are on each intermaxillary 8 or 9 of moderate size; 

 on one side many small intermediate teeth are present. The number of teeth in the lower 

 jaw varies ti-om 13 on the one side to 21 on the other. 



The first branchial arch has 13 gill rakers, the longest of which measures about 2 milli- 

 meters. The second arch has about the same number, while on the third there are but 6 or 



