GAEMAX: THE CHIMAEKOIDS. 247 



gized with dorsal spines, or with the illicia of the Lophioids, though 

 treated as if of similar nature by early authorities. 



The function of the tenacula below the bases of the ventral fins is 

 somewhat like that of the series of erectile hooks on the upper sides of 

 the pectorals of some Platnsoiuia, Raia ocellata, for instance. 



The lateral canal systems of Rliinochimaera and Harriotta are made 

 up of pseudotubules, tubes narrowly slit outwardly ; tliat of Callorhyn- 

 chus consists of tubes, and that of Chimaera is a system of grooves. 



The spiral intestine of Rhinochimaera is similar to that of the other 

 livin<r Chimaeroids. 



Tlie first dorsal is short, erectile, and has a spine and radials in all 

 members of this group. 



The second dorsal is long in the Chimaeridae, of medium length in 

 the Rhinochimaeridae, and short in the Callorhynchidae. 



The armature of the supracaudal fin is peculiar to Rhinochimaera. 



The claspers of Rhinochimaera and Harriotta resemble one another ; 

 except in being simple, they are unlike those of Callorhynchus ; in those 

 of the Chimaeridae the cartilages are trifid. 



The claspers, intromittent organs, are possessed by "both Plagiostomes 

 and Chimaeroids ; the tenacula of the latter are peculiar to them. 



The position of the clasper of the Chimaeroid is rather above the edge 

 of the ventral ; that of the Plagiostome is below it. 



Certain peculiarities of the Chimaeroids, especially of skull and brain, 

 are perhaps best accounted for by supposing the group to have been 

 derived primarily from a short-snouted and short-faced form, acquisition 

 of the long snout and the prognathous condition of the skull afterward 

 carrying the olfactory lobes and the hemispheres forward and separat- 

 ing them from the balance of the brain and from one another, and in 

 Chimaera a still later loss of the snout and shortening of the anterior 

 part of the skull bringing the lobes and the hemispheres together into a 

 single mass. 



D 



Rhinochimaera pacifica. 



Plate 1, Fig. 1. 



Hariotla pacljica Mitsukuri, 189,5, Zool. Mag. Tokyo, VII., without description. 

 Rhinochimaera pacijica Garman, 1901, Proc. N. E. Zo<"il. Clul), II., 75. 



The specimen here describeil is a fully developed male of about tliii'ty-?ix 

 inches in length, before a slight loss from the filamentary e.xtremity of the tail. 

 On account of the figure some of the details of shape need not be dwelt upon 



