TENTATIVE ARRANGEMENT OF THE GENERA OF .\m ' n >hi m.L. 



I. Body oblong, compressed. Teeth in jaws in villiform bands. 



A. Pectorals present. 



1. Dorsal anil anal fins touching (or nearly so), the same vertical, or overlapping. 



:i. Lateral line not at all, <>r but Blightly, enlarged. Scales cycloid, s >th. 



i. No luminous glands mi head or tail. (Luminous scales sometimes present on tail, ahore or 

 below,) 

 \. Head short, with limb <>i' preoperculum nearly vertical; Bnout more "i less hinnt 

 and declivous. Precaudal photophores 2. 

 1 tarsal entirely in front of anal, and scarcely, or not at all, overlapping. Superanal 



photophores iu two groups Myctophum 



Dorsal overlapping anal. Superanals in one or two groups Benthosema 



xx. Head long, limb of preoperculum oblique, snout oonical and snake-like, l'reeandal 

 photophores i or 2 + 1. 

 Dorsal about equal to or shorter than anal, and not overlapping. 



No orbital spines Lampanyctus 



Orbital spines < iERATOSCOPELUS 



Dorsal much longer than anal, and overlapping it. 



Pectorals placed normally N SCOPELUS 



Pectorals placed very low CATABLEMELLA 



ii. Luminous gland* on toil, but none on head. 



x. Dorsal and anal nearly equal, not touching same vertical. 



Read somewhat conical, with limb of preoperculum Blightly oblique. 



Saddle-like gland on tail, a hove and below Lampadena 



iii. Large luminous glands on haul, but none on tail. 

 x. Superanal photophores in two groups. 

 Precaudal photophores 1. 



One large, irregular gland occupying entire front of head vEthoprora 



Four luminous glands on head, one in front of each eye and one on each 



infraorbital COIXETTIA 



Precaudal photophores none. 



A gland in front of each eye below the nostril. 



Photophores and cephalic glands all divided into halves by horizontal septa 

 of black pigment. DlAPHUS 



b. Lateral line obsolescent. 



i. No luminous glands. Photophores much a* in typical genus. 

 x. Head long, with oblique preopercular limb. 



Dorsal overlapping anal, the latter much the longer. Pectoral inserted high up. 

 Precaudal photophore 1. Apparently no photophores on head-TARLETONBEANIA 



c. Lateral line with scales much enlarged; scales hard, persistent. 



i. Luminous gland* or scales on top of caudal peduncle, none on head. 

 x. Scales cycloid. Anal passing behind soft dorsal. 



Body elongate, fusiform; head short, with projecting snout. 



Anal much longer than dorsal, but not overlapping. Caudal peduncle slender, 

 elongate. 

 One posterolateral photophore over break in superanal series. 



Rhtnoscopelus 



Body ovate, compressed; head short, profile declivous; snout not projecting. 



Anal somewhat longer than dorsal and overlapping it slightly. Caudal peduncle 

 short and stout. 

 No posterolateral photophore. .Superanals in unbroken series. .ELECTRONA 

 xx. Scales ctenoid. Anal terminating below soft dorsal. 



liody elevated, somewhat compressed. Caudal peduncle rather rlender. 



Anal longer than dorsal, but scarcely overlapping Dasi 8COFKLUS 



2. Dorsal and anal short, similar, far apart. 



a. Scales large, very deciduous, covered with minute spines. 



i. No luminous glands on Itead or tail. 



x. Scales along belly with luminous centers. Photophores far from normal. 

 Head conical: rictus short. 



Dorsal and anal equal, the latter placed with its center under soft dorsal. 



NEOSCOP] 1 is 



b. Scales (if present) very deciduous. 



i. Mouth very large; maxillary much dilated at tip Scopelje m. ys 



B. Pectorals rudimentary. 



1. Dorsal and anal overlapping considerably. 



a. Luminous glands on tail, above and below. Photophores minute, irregularly placed. 



i. Head long, with oblique preopercular limb; Snout conical; mouth terminal, hori- 

 zontal Nannobrachium 



II. Body elongate, cylindrical. Teeth in lower jaw in several series SCOPELOSAURUS 



