THE LONG-SNOUTED CHIMAEROID OF JAPAN. 7 



They are located usually in pairs and together straddle the rim of the 

 fin, causing this in profile to appear somewhat serrate. The denticles 



themselves are somewhat tumid, imperfectly calcified. 



In the male dermal denticles occur in the customary positions : 

 1.1 .. on the frontal and on the two ventral pairs of clasping organs. 

 The condition of the frontal clasping spine is illustrated in PL I, 

 Fig. 8 </. The antero-ventral pair of clasping organs is shown in the 

 same plate, Fig. 8 a, b, and of these the stout recurred marginal den- 

 ticles differ little from those in Chimaera. The denticles on the mixi- 

 pterygium are also essentially similar to those of the other genera. 

 In connection with the mucous canal system, however, I fail to find 

 in " Harriotta " the distinct dermal supporting plates well known in 

 Chimaera. We thus find that the mucous canals of the suborbital 

 region are not provided with prominent and almost plate-like supports: 

 one infers, how r ever, that these supports are present in a reduced form 

 after drawing a needle sharply along the floor of a canal. It is ob- 

 served that in " Harriotta " the mucous canals, although distinctly of" 

 the chimaeroid pattern, do not open widely to the surface, as in the 

 case of many bathybial forms. So closely are the opposing margins 

 drawn together 1 -* in this type that the point of a common needle can 

 hardly be drawn through the canal without causing its margins to se- 

 parate. In the disposition of the sensory canals, " Harriotta " ap- 

 proaches more closely Callorhynchus than Chimaera. 



HI. Skeleton. PI. I, Figs. 4. \a, 5, (5, 6a, 7. 



The skull, as has already been noted, retains a well-marked line 

 showing where the palato-quadrate is completing its fusion with the 

 skull. It may be noted that this distinctness of the palato-quadrate 



1) This condition can hardly be due to artifact since it does not occur in the case of the 

 allied forms, Callorhynchus or Chimaera, when similarly preserved. 



