THE LONG-SNOUTED CHIMAEROID OF .JAPAN*, [g 



radalia, is prominently marked oil' on the preaxial region of the fin, a 

 structural difference from other chimaeroids, correlated doubtless with 

 a srreater decree of movement of the anterior rim of the fin. It is to 

 be noted that the element best known as mesopterygial has attained 

 considerable physiological importance, functioning as a kind of 

 "humerus" for the fin. It is a stout narrow plate possessing 

 considerable mobility, both at its juncture with the shoulder girdle 

 and with the pro- and metapterygial elements. The shoulder giadle is 

 strong, even for a chimaeroid, especially in its ventral moiety. 



The ventral fin is notably narrowed — i.e., antero-posteriorly. 

 Basalia, greatly constricted, are represented in a single oblong 

 plate, with which fuse also the two most anterior radiais. The 

 anterior margin of the supporting lobe of the fin is formed, is in the 

 pectoral fin, by an encircling row of stout cartilages, which doubtless 

 represent the distal segments of the anterior radiais. The most 

 anterior element of this row of supports is an elongated cartilage 

 which may represent either the distal end of the first radial, or, more 

 probably, a union of this element with a still more anterior cartilage. 

 In the present example twelve distinct radiais are counted. Posterior 

 to the fin proper, and loosely attached by ligament to the plate of fused 

 basais appears a rudiment of the mixipterygium of the male. This 

 structure, now noted for the first time in a chimaeroid,* is seen to 

 consist of two short and delicate segments. A further peculiarity 

 of the pelvic fin is the greatly reduced size of its articulation to the 

 girdle. The girdle itself is small, thin and delicate. Its upper blade 



* The rudimentary " clasping organ " is so well known in female sharks that the present 

 writer was led to represent it in such a condition in his " Fishes Liviug and Fossil." Unfor- 

 tunately he did not think it necessary at the time to insert the word " rudimentary " in the 

 brief explanation attached to this figure, and he has therefore caused Dr. C. F. Jungerson to 

 believe that it was his intention to append a functional " clasping organ " to a female shark ! 

 Jungerson's misunderstanding would not have occurred had lie taken the pains to consult the 

 text which accompanied the figure. 



