526 BULLETIN 100, UNITED STATES NATIONAL MUSEUM. 



its posterior margin is bilobed, being divided by the anus ; the organ 

 is raised above the surface of the body, has a clear glassy appearance, 

 and is punctulate on its outer face ; this posterior organ is connected 

 by a median black strand of tissue with the anterior lens-like body, 

 which is similar but much smaller, and is located before the ventrals. 

 There can be little doubt that these structures are homologous with 

 those described by us in other species of this genus and in species of 

 other genera, as in C oelorhynchus argentatus (p. 435). 



Many of the scales still remain on a few specimens. These scales 

 are beset with short, weak spinules, as in other species of the sub- 

 genus, being similar in arrangement to those figured for II. langipes. 1 

 The midline of the belly, even over the anterior lens-like organ, is 

 scaled, contrary to a statement in the original description ; the scales 

 themselves are usually lost, but the scale pockets can be made out. 

 The position of the lateral line was incorrectly given in the type de- 

 scription; it rises anteriorly, as in II. longipes, so that there are 3, 

 instead of 5, large scales from the end of the first dorsal to and in- 

 cluding the lateral line series. 



The striation of the abdominal region agrees in its wide extent 

 with that of H. striatissimus, italicus, and cavernosas. The striated 

 region includes the area encircling the base of each ventral fin, and 

 regions extending backward about half way to the anus, upward 

 to before the pectoral base, and forward along the entire sides of 

 the isthmus; the gular membrane is completely covered by similar 

 but somewhat finer striations, in addition to the cross lines of black, 

 which are less sharply developed than in most species. 



Branchiostegals 7, as in all other species examined. Gunther's 

 count of 6 in his longibarbis is doubtless an error, due to the small 

 size of his type specimen. 



Table of fin-ray counts. 



Type. 



(longiceps, in reference to the comparatively long, slender head.) 



1 Proc. U. S. Nat. Mus., vol. 43, 1912, pi. 23, fig. 1. 



