36. QENYOEOaE. 177 



a. Adult. India. Presented by Sir J. Richardson. 



b. Adult : stuffed. Louisiude Arehipelago (15 fathoms). Voyage 



of the llattlesnnke. 



c. Adult: skeleton. Amboj-na. From Mr. Frank's Collection. 



d. Adult : stuffed. Mozambique. Presented by T. Thompson, Esq. 



Skeleton. — The skull Ls distinguished not only by the development 

 of all the bones situated in a vertical direction, as we find usual in 

 Oenyoroge, but by much more developed mucifcrous channels than 

 in G. bengalensis, offering a fiu'ther example of how little importance 

 is the generic character di'awn from this modification of the bones. 

 The occipital crest is exceedingly high, with a roimdcd superior 

 angle, and extends far between the orbits ; in front it is separated 

 into two laminae, which, parting from each other in G. bengalensis, 

 are close together in this species. There are two other ridges on 

 each side of this crest, both arising from above the orbit : the in- 

 terior, parallel to the occipital crest, articulates with ont of the 

 processes of the suprascapula, and terminates behind in a prominent 

 spinous point ; the exterior muciferous ridge descends in an oblique 

 direction and articulates with the other process of the suprascapiila. 

 The space between the eyes is very uneven on account of ridges and 

 cavities. The pi-aeorbital bone is large, as large as the area of the eye, 

 trapezoidal, and partly excavated by flat and low muciferous cavities ; 

 the suborbital arch muciferous, but otherwise as in G. bengalensis. 

 The maxillary bone short, not longer than the pra;orbital, gradually 

 widening behind, with a nearly straight-lined upper edge and a 

 rather concave one beneath. The operculum has only one veiy 

 short point, forming the end of an interior low crest ; there is only 

 a rounded prominence at the place where another point is generally 

 found ; it is produced by an emargination beneath. The prasoper- 

 culum is minutely serrated above and partly in the notch, the den- 

 ticulations being coarser, and radiating at the angle and the inferior 

 limb ; the sub- and interoperculum are entire ; the knob of the 

 latter is an obtuse point directed upward. The coracoid bone as in 

 O. bengalensis. 



Of tlie entire system of muciferous channels, that pair running 

 along the upper surface of the skull is most developed ; it is formed 

 by the turbinal, entirely modified into a tube, and by the prineii)al 

 frontal bones. This channel has three openings : in front, the 

 anterior opening of the turbinal ; secondly, an opening formed by a 

 turbinal and frontal bone together ; finally, a third in the frontal 

 bone alone, above the anterior margin of eye ; this channel is blind 

 behind and does not commimicate with the second, as in Acen'na 

 eeimua. The second arises from above the posterior margin of the 

 orbit, and soon separates into two stems: one of them, the scapular 

 stem, follows the exterior ridge on the parietals, and being curved 

 upwards and backwards, passes into the suprascai)ula and the upper 

 suprascapular process, where it is lost : the other, the suborbital 

 stem, follows the .suborbital arch and expands on the prteorbital ; its 

 openings arc small and irregular. The third, or rather the fourth 



