DISCUSSION OF SPECIES AND THEIR DISTRIBUTION. 205 



Lepidoi>us. Top of head very flat, concave between tlie eyes, with no occipital crest. Iiiter- 

 orbital ridges not elevated. Eyes large, slightly postiucMlian. Operculum ohiong, reacliiiig 

 a little beyond the base of the pectoral flu. Nostrils Iiorizoutal, iu front of the eves. 

 Supramaxillary not extending to vertical from front of eyes. Lower jaw with stout cutau('- 

 ous ap])endage. 



Three very long, simple, compressed teeth on each intermaxillary iu 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 iu the upper Jaw, largest 

 in the middle of the jaw. Palatine teeth minute. 



Dorsal fin, bogiuuiug above the operculum, nearly uniform iu height throughout its 

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

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

 spines very numerous (numbering with the rays about 100 in B. dongafus, all except 28 or 30 

 being spines), minute and almcist 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 eacli by a minute scale- 

 like spine, inserted below the origin of the pectorals. 



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

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

 (In Lcpidopus caudatm all the arches are supplied with several series of rakers.) 



Bcnthodesmus may be distinguished from Lepidopm and JEvo.rymetopon by the following 

 salient characters: 



1. The slenderer, lower form of the body, the height of which iu B. dongafus at the 

 vent is one-fourth the length of the head; in Lcpidopns 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 flat 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 

 Benthodfsmus under the base of the pectorals. 



6. In the presence of a single small postanal scute, in place of the two hirger ones iu 

 Lepidopus. 



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



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



Benthodesmits elongatits, GooDE and Bean, Proc. U. S. Nat. Mus., iv, 1881,380-3, Figure.— Jordan and Gil- 

 bert, BuU. XVI, U. S. Nat. Mus., 1883, 910.— Jokd.vn, 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 [)eduucle 

 half of greatest height of body. Least height of tail one-third width of interorbital area. 



Length of bead contained seven and a half times iu 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 

 2i times in length of head. Upper jaw not reaching to vertical fi-om anterior margin of 

 eye, and equal in length to the postorbital portion 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 eipuil to half 

 the length of the snout. 



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

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

 jaw varies from 13 on the one side to 21 on the other. 



The flrst 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 



