32 PKOCEEDINGS OF THE NATIONAL MUSEUM vol.76 



A diagram of the type specimen is rendered in the accompanying 

 Figure 15, the species not having been previously illustrated. 

 Known only from Japan. 



DIAPHUS GLANDULIFER Gilbert, 1913 



Material investigated. Type specimen No. 74472, U.S.N.M. 



Accurately and adequately described and figured by Gilbert, 1913 

 (p. 90 and pi. 11, fig. 2). Correctly defined in the previously 

 rendered key. 



Known only from Japan. 



DIAPHUS RAFINESQUEI Cocco, 1838 



NyctopJius rafinesquci Cocco, 1838. 



Diaphus rafinesquei Pakb, 1928 (with full synonymy). 



Diaphus theta Eigenmann and Eigenmann, 1891 ; Goode and Bean, 1895 ; 



Jordan and Eveemann, 1896 ; Bkaueh, 1906. 

 Myctophum protoctilus Gilbert, 1891. 

 Diaphus nanus Gilbert, 1908 and 1913. 



Material investigated. Type lot of Diaphus theta Eigenmann 

 and Eigenmann, 1891, No. 41914, U.S.N.M. (2 specimens). Type 

 specimen of Myctophum protoculus Gilbert, 1891, No. 44290, 

 U.S.N.M. Type specimen of Diaphus nanus Gilbert, 1908, No. 

 75765, U.S.N.M. 



The claim of D. theta Eigenmann and Eigenmann to specific dis- 

 tinctness from D. ra-ftnesgynei Cocco has heretofore been mainly or 

 entirely based upon the alleged smaller size of the eyes in the type 

 of the former nominal species. An examination of the type speci- 

 mens, however, served to show that no such difference seems to exist, 

 the eyes of D. theta being quite as large as those of the normal 

 D. rafinesquei, with a diameter equalling more than one-third of 

 the length of the head or 10 to 12 per cent of the total length without 

 caudal fin. D. theta is therefore herewith included among the 

 synonyms of D. rafinesquci. 



The identity of Myctophum protoculus Gilbert with D. theta 

 Eigenmann and Eigenmann has already been realized by the author 

 of the former species (footnote by Gilbert in Jordan and Evermann 

 1896, p. 564), and could only be further confirmed by an inspection 

 of the tyj)e. 



The lack of taxonomic differences between the descriptions of 

 Diaphus nanus rendered by Gilbert, 1908 and 1918, and the current 

 descriptions of D. rafinesquei Cocco has already previously prompted 

 the author to include the former name among the synonyms of the 

 latter species (see Parr, 1928, pp. 131 and 135). This opinion 

 stands unaltered after examination of the type specimen of D. ncmus. 



