1936] Schultz: Keys to Fishes 151 



branes near their margin, or in spots forming an obscure longitudinal bar 

 near base of fin, or in faint mottling s on both rays and membranes (in 

 pale and unmottled specimens, membranes and rays about equally pig- 

 mented). Range: Introduced into most of the streams and lakes of 

 United States. Freshwater. Common. 



Catfish. Horned Pout 105. Amciuriis nebulosus (LeSueur) 



Family 32. Sudidae (=Paralepididae) 



Range : Puget Sound. Marine. Rare. 



Pelagic Fish 106. Arctozenus coruscans (Jordan and Gilbert) 



Family 33. Myctophidae. 6 Lantern Fishes 



la. Luminous scales absent or present in varying numbers and positions ; but no 

 large infra.- or supra.- caudal plates, the median luminous tissues or 

 glands above and below the caudal peduncle are, when present, always 

 divided into separate organs, each occupying the space and position of only 

 one single normal scale, in an overlapping series ; or the entire tissue may 

 in some cases be confined to the space of only 1 single scale altogether, but 

 never expands as an undivided organ beyond the size of a scale. Fig. 9. 



2a. (See 2b and 2c.) Only 2 precaudal organs, usually well separated from 

 the posteroanal series, very rarely confluent with the latter, median lu- 

 minous scales often present infra.- and supra.- caudally, according to the 

 sex, but only rarely found in both positions on the same specimen ; no 

 luminous scales on any other part of the fish, antorbital organs not con- 

 spicuously enlarged ; photophores without a black dividing septum. 



3a. Ventral organs 6 ; posterior-lateral organ 1 ; anal organs in 2 separate 

 groups ; suprapectoral organ above base of pectoral fins ; scales ctenoid. 

 Range : Washington to San Diego. Marine. Not common. 

 107. Myctophum crenulare Jordan and Gilbert 



3b. Ventral organs 4 ; postero-lateral organ 1 ; anal organs in 2 separate 

 groups ; supra-anal organs 3 ; supra-pectoral organ above base of pec- 

 toral fin; 2nd ventral organ in a line with rest of the series; scales 

 smooth (cycloid) ; supra-anal organs angulate ; anterior supra-anal or- 

 gan approximately on the same level as second supra-anal organ, the 2 

 organs being on a more nearly straight line with the supraventral or- 

 gan, than with the last (superior) supra-anal organ. Range: Wash- 

 ington to San Diego. Marine. Not common. 

 108. Myctophum californiense Eigenmann and Eigenmann 



2b. (See 2a and 2c.) Precaudal organ, when separate from the postero-anals, 

 present in the numbers of 3 to 6, never 2 only ; the lower precaudals may, 

 however, in many forms be quite confluent with the posterior anals, in 

 which case their numbers can not be made out ; median series of luminous 

 scales usually present both infra.- and supra.- caudally in the same speci- 

 men; similar scales are also common on other parts of the body, partic- 

 ularly along the bases of dorsal and anal fins ; the 2 subpectoral organs 

 rarely or never form a straight series with the 1st thoracic organ; antor- 

 bital organs not conspicuously enlarged ; photophores without dividing 

 septum; 4th thoracic organ elevated considerably above the rest of this 

 series; subpectoral organs not above the pectoral fin base; luminous scales 

 sometimes found at or before the adipose dorsal fin, but otherwise only 

 on the caudal peduncle; no dorsal glands. 



"This key has been modified after the publication by A. E. Parr (1928), Bull. Bing- 

 ham Oceanographic Collection. 



