Fig. 192 — Capture localities in the eastern Pacific Ocean for Bolinichthys photothorax 

 (solid circles) and fi. longipes (open circles). 



Ceratoscopelus Giinther, 1864 



Very similar to genus Bolinichthys but first 4 PO on same level; only P0-, elevated. Five 

 VO, not on same level. Palatine teeth in single series, the anterior few slightly enlarged. No 

 Dn; Vn small, rounded. PLO, SAO3, upper Pol and Pre below but touching lateral line; VLO 

 about midway between pelvic origin and lateral line. Numerous patches of luminous tissue 

 (scales) occur along dorsal and ventral midlines and on other parts of the body but are easily 

 lost; most persistent is the Y-shaped series of scales between pelvic and anal fins and those 

 along base of anal fin and in caudal luminous glands. 



There are at least two forms in the eastern and central Pacific Ocean that conform to the 

 above diagnosis. As presently understood, these forms are separable only by the presence or 

 absence of some luminous scales on head and body, and, possibly, the extension of these scales 

 along the secondary (procurre^t) caudal rays. Unfortunately, as some luminous scales are 

 easily lost, only specimens in good condition may be properly allocated; given such specimens, 

 the following key will aid in determining two basic forms. 



Key to species of Ceratoscopelus 



la. Prominent patches of luminous tissue over each eye (supraorbital luminous gland). Pec- 

 toral fin seldom reaching past AOa^. No luminous scales between PVOi.j and PO2-3 over 

 PO4, or over anus. Luminous scales on caudal peduncle usually not extending beyond 

 vertical from Pre. C.townsendi 



lb. No supraorbital luminous gland. Pectoral fin usually reaching AOa:j or AOa^. Luminous 

 scales present between PVO,.. and PO:;;), over POj, and over anus. Luminous scales on 

 caudal peduncle extending to or beyond a vertical from Prca or Prc4 C. warmingii 



205 



