6 



PKOCEEDINGS OF THE NATIONAL MUSEUM 



VOL. 76 



Mycto'phum^ particularly with regard to the distances from the 

 snout to the ventral and vertical fins, as will appear from the 

 following table of measurements : 



Measurements of M. crenulare Jordan and Oilbert 

 [In per cent of the total length without caudal fin] 



Crenulare 



Type of.. 



Total length without caudal fin in mm 



Length of head 



Diameter of eye 



Greatest height 



Length of lower jaw 



Height of caudal peduncle 



Snout to D 



Snout to V 



Snout to A 



The illustration of the species previously rendered by Goode and 

 Bean (1895, fig. 105, pi. 28, Tarletonbeania tenua), being rather in- 

 adequate and misleading in several respects, the accompanying dia- 

 gram has been prepared from the above recorded specimens.® 



Correctly defined in the previously rendered key. 



M. creTmlare has been taken only off the Pacific coast of North 

 America. 



MYCTOPHUM IMITATOR Parr, 1928 



Myctophum suiorMtale Gilbert, 1913 (name preoccupied, see Parr, 1928, 



p. 60). 

 Myctophutn simile Taaning, 1928. 



Material investigated. Type specimen of Myctophvmi subarbitale 

 Gilbert, No. 74473, U.S.N.M. Suruga Bay, Japan. 



The predorsal length of the type specimen is recorded by Gilbert 

 1913 as 55 per cent of the total length without caudal fin, but was 

 found by the author to be only 45 per cent of the said measurement, 

 the discrepancy probably being due to a misprint in Gilbert's report. 

 The length of the head was likewise found to be probably more 

 nearly 32 per cent of the total length without caudal fin, than 35 

 per cent as recorded by Gilbert. The distance from snout to ventral 

 fins equals about 41 per cent of the same measurement. 



No illustration of the species having previously been rendered the 

 accompanying diagram was prepared from the type specimen. 



Correctly defined in the previously rendered key. 



Known only from the coast of Japan. 



« The figure represents a composite diagram, photophores which have become accident- 

 ally lost on the left side shown of the type of M. crenulare, on which the drawing is 

 primarily based, have been entered by comparison with the right side and with the type 

 of Tarletonbeania tenua. 



