152 



with growth. No barbel. Dorsal opposed to ventrals, its origin 

 far before that of anal, above the hindpart of which the small 

 adipose fin is situated. Pectorals below the middle of the height. 

 Caudal forked. Minute teeth in several rows on jaws, vomer, 

 palatines, pterygoids and tongue. Gillmembranes free from each 

 other and from isthmus. Pseudobranchiae present. Gillrakers 

 long. 8 10 branchiostegal rays. Luminous organs on head, at 

 least one before eye, 2 behind praeopercular margin, 3 on 

 branchiostegal membrane; for those on the body see below. 

 There may be infra- and supracaudal luminous scales or plates. 

 (Fig. 59)- 



In describing the luminous organs on the body we follow 

 the terminology of Brauer as shown in fig. 58. 



AOa 



Fig. 58. My c top hum laternatum Garm.| (after Brauer). 



PO = Maculae pectorales 

 PVO = M. subpectorales 



VO = M. ventrales 

 AOa = M. anales anteriores 

 AOp = M. anales posteriores 



Pol = M. postero-lateralis 



Prc = M. praecaudales 



PLO = M. suprapectoralis 



VLO = M. supraventralis 



SAO = M. supraanales 



a = antorbital organ 



br = branchiostegal organs 



o = opercular organs. 



Synopsis of the species. 



I. Luminous organs not divided by a black septum. 



A. Infra- and supracaudal luminous scales. (Lam- 



panyctus}. 2 Pol, luminous organs kidney shaped M. micropterum p. 154. 



B. No luminous scales. (Myctophum). 



I. Upper jaw extending to vertical through 

 posterior margin of eye, its posterior end 

 strongly dilated. 



a. 2 Pol M. benoiti reinhardti p 155. 



b. I Pol. 



