562 Bulletin 47, United States National Museum. 



c. Luminous patches above and below tail, occupying nearly whole length of caudal 



peduncle. LEUCOPSARUM, 841. 



cc. Luminous patches above and below tail short. NANNOCHIR, 842. 



bb. Gill rakers 5 + 10; caudal spots 3, the last above end of lateral line; snout rather 



acute; photophores minute. MEXICANUM, 843. 



aa. Anal spots small, 16 to 18. 



d. Anal rays 19; eye moderate or small, 5% to 5% in head; caudal spots 3 or 4, the last 

 well separated near end of lateral line; last ray of dorsal over sixth of anal; size 

 large. REGALE, 844. 



dd. Anal rays 16 or 17; eye 5 in head; last ray of dorsal over fifth of anal. 



MACDONALDI, 845. 



841. NANNOBRACHIUM LEUCOPSARUM (Eigenmann & Eigenmann). 



Head 3f to 3| ; D. 12 to 15 ; A. 14 or 15 ; scales 35 or 36. Caudal pedun- 

 cle deep, its least depth about half that of body. Luminous patches 

 above and below tail, occupying nearly the whole length of caudal pedun- 

 cle ; caudal spots 3 or 4 ; anteroanal spots usually 6 ; ventral spots 5 ; 

 1 or 2 posterolateral spots. Body deep forward, the head long and 

 pointed ; maxillary shortish, reaching edge of preopercle, 1| in head ; 

 cheek broader than in N. nannochir, less tapering behind; eye rather 

 small, 3$- in head. Scales very thin, those of the lateral line much deeper 

 than others ; pectoral very short and narrow. "Color rather pale ; oper- 

 cles with silvery luster ; iris with silvery pigment ; fins not quite black. 

 Length 4 inches. Alaska to San Diego, in rather deep water; not rare. 

 Locally very abundant in stormy weather off Point Loma. (/levof, 

 white; ipapbg, spotted, piebald.) 

 Myctophum (Stenobrachins) leucopsarum, EIGENMANN & EIGENMANN, Proc. Cal. Ac. Sci., March, 



1890, 5, off Point Loma, Lower California, in stomachs of Sebastodes. (Type, No. 



41916. Coll. Eigenmann.) 



842. NANNOBRACHIUM NANNOCHIR (Gilbert). 



Very close to Nannobrachium leucopsarum, differing chiefly in the longer 

 body and head, and especially in the less development of the luminous 

 patches on the tail. 



Head 3i to 3| in length ; depth 5. D. 12 or 13 ; A. 15 or 16 ; scales 35 or 

 36. Gill rakers 5 + 13 to 15 ; caudal peduncle long and slender, its least 

 depth | to i that of body ; luminous patches on tail short, usually occu- 

 pying i to i length of caudal peduncle. Maxillary long, the preopercle 

 very obliquely placed ; the cheek long, tapering to an acute angle pos- 

 teriorly. Anal spots 7 + 7. Ventral spots usually 5 ; no spot before eye. 

 Coloration darker than in N. leucopsarum, the opercle black, the iris 

 usually with silvery, the fins uniformly black. Length 5 inches. Alaska 

 to Santa Barbara Islands, abundant in 300 fathoms, often in company 

 with Nannobrachium leucopsarum, which it very closely resembles, (vdvvoc , 

 dwarf; % i-Pi hand.) 



Myctopltum nannochir* GILBERT, Proc. U. S. Nat. Mus., 1890, 51, July. (Types, No. 1059, Stan- 

 ford Univ. Mus., and 44291 U. S. Nat. Mus. Coll. Albatross); from station 3072, off 

 coast of Washington. 



* Reexamination of the original types of Myctophum nannochir showed to Dr. Gilbert that two 

 species were confounded by him under that name. One of these was almost simultaneously 

 described by Eigenmann under the name of leucopsarum. The name nannochir has been restricted 

 by Gilbert to the other. 



