]MYCTOPiiUM ArR()LATKn\ATr:\r. 2G5 



as tlie eye, narrower tlian deep, I)luiilly roimded in IVont, inteniiirial keel 

 on the skull low. Eve large, twice as long as the snout, one and one I'ourth 

 times as wide as the interorljital space, nearly one third of the length of the 

 head ; orbit not cutting into the u])per profde. Mouth wide, reaching more 

 than halfway from the snout to the base of the pectoral, about twice as long 

 as the eye ; maxillary reaching backward of the orbit one half the ocular 

 diameter. Teeth small, in narrow villil'orm bands on intermaxillaries, denta- 

 ries, and palatines, and in a small group at each side of the vomer. Gill 

 openings -wide ; membranes hardly united, free from the isthmus. Gill 

 rakers more than half as long as the eye, slender, compressed, five plus thir- 

 teen. Preopercular ridge low, no spine at its junction with the postorbital 

 ridge. Scales large, larger on the lateral line, three above the line and four 

 below it, seven to nine from the adipose fin to the caudal. 



Third ray of the dorsal flu U)id\vay from the snout to the base of the 

 caudal ; basal length less than one and one half times the length of the eye, 

 base above the middle of the space between the ventrals and the anal. Adi- 

 pose fin distant from the base of the first dorsal one and one half lengths of 

 the latter, or from the base of the caudal one length of the dorsal base wliicli 

 is half the length of the head. Ventral base slightly in advance of the verti- 

 cal from the first ray of the dorsal. Anal origin little liackward of the last 

 ray of the dorsal ; anterior two rays and all those behind the middle of the fin 

 short; hindmost three rays below the adipose fin. Caudal deeply forked. 



The arrangement of the lanterns, light organs, light facets, etc., does not 

 differ very nuicli from that seen on M/j'ctophiim Caninianum. There are 

 three to four facets in the mandibular and branch iostegal series ; a small 

 one lies at the end of the mouth cleft and a larger one above it at the end 

 of the maxillary ; one lies on the base of the pectoral, above and forward of 

 it at the edge of the operculum halfway to the lateral line another, and 

 below and forward half way to the ventral sories a third ; one lies at the 

 origin of the ventral and above it midway to the lateral line another; above 

 the vent there is a series of three, the uppermost a little below the line, and 

 behind this upper one halfwa}' to the base of the caudal, close to the line, 

 there is a single one ; in the ventral series there are four from the isthmus 

 to the ventrals, four from the ventrals to the anal, ten along the base of the 

 anal fin, six below each side of the caudal pedicel, and two at the base of 

 the caudal. Three considerable spaces separate the groups backward of the 

 vent, the lanterns being quite close together in each group. 



