42 PROCEEDINGS OF THE NATIONAL MUSEUM vol.76 



covering any differences between the type specimens of these two 

 species with regard to their circumorbital organs. 



T), adenomus has otherwise been quite accurately and adequately 

 described and figured by Gilbert, 1905 (p. 592 and pi. 68, fig. 1), 

 and correctly defined in the previously rendered key. 



The distance from the upper end of the base of pectoral fin to 

 the PLC was found to be 4.5 mm., the distance from PLO to the 

 lateral line canal being 8 mm. 



The type specimen is a female. 



The statement rendered by Fowler, 1928 (p. 68), that this species 

 is "possibly not distinct from D. coeruleus (Klunzinger)" would 

 equally well apply also to the rest of the four species mentioned in 

 the key on page 37, if the presence or absence of a supraorbital 

 organ should prove insignificant as a taxonomic character, or if such 

 organ should appear to be present also in the true D. coeruleus. The 

 former possibility seems rather remote, however, and the latter 

 possibility is not indicated in either of the descriptions of D. coeruleus 

 given by Klunzinger, 1871, and by Brauer, 1906. 



It must on the other hand also be admitted that none of the four 

 species would be satisfactorily differentiable from each other or from 

 D. coeruleus on the basis of the photophores of the body alone, and 

 the differences in proportions would also seem comparatively insig- 

 nificant if not supplemented by differences in other respects. 



D. adenomus is known only from Hawaiian waters. 



DIAPHUS EFFULGENS Goode and Bean, 1895 



Aethoprora cffulgois Goodb and Bean, 189.5. 

 Diaphus effulgens Parr, 1928 (with full synonymy). 



Material investigated. Type specimen No. 43770, U.S.N.M. 



The original description of this species (Goode and Bean, 1985, 

 p. 87) being in several aspects quite inadequate with regard to the 

 distribution of the photophores, it has been deemed advisable to 

 render a full account of the arrangement of these organs in the type 

 specimen and a diagram has been prepared for convenience in 

 interpreting the description. 



The upper and lower antorbitals on each side have become fused 

 to form a pair of very large luminous organs,^^ occupying practically 



** See p. iiS. To avoid confusion by the use of the key to the species the fused upper 

 and lower antorbitals were in the previous treatise on these fishes designated simply as 

 lower antorbitals, in accordance with the precedent set by Brauer, 1906, and generally 

 followed in the later literature, although the author was already at that time strongly 

 inclined to doubt the correctness of the homologization implied by the use of such termi- 

 nology. (See Parr, 1928, p. 140.) The supraorbital organs were correspondingly desig- 

 nated as upper antorbitals. According to the new terminology, herewith introduced, the 

 definition of Division IX (Parr, 1928, p. 120) should read: A small supraorbital organ on 

 each side. Upper and lower antorbitals completely fused. The latter character then 

 distinguishes this division from the division treated on p. 37 in the present report. 



