Garman.] 200 [May 2, 



Callorhynchus has very complex pelvic holders. On the outer side 

 of the broad primary of each there are blades which unfolded as- 

 sume a fan shape. On the opposite or inner side each has a compli- 

 cated, somewhat glandular sac, of which the mouth is closed by 

 attempt to force its contents outward. The mouth being shut, the 

 contained liquid is driven through a small cartilaginous tube, which 

 connects with the sac and extends outward far enough to reach the 

 groove of the penis, when it is turned forward, and through the lat- 

 ter the fluid is conveyed to the oviducts of the female. The position 

 of the openings of the spermatic ducts and their distance from the 

 grooves renders it difficult to see how the semen can be introduced 

 into the oviducts without previous mixing with the water ; but 

 serious objection to this supposition vanishes on consideration of the 

 methods practiced by Batrachians and Fishes, in which fertilization 

 takes place only after both ova and sperm are thrown into the 

 water. 



Chimssra has a more simple form of holder. The articulation, 

 position of receptacle, and the muscles by which it is thrown out are 

 similar, but the organ itself is simply a broad rounded plate bearing 

 on its inner edge a row of sharp hooks directed toward the base. It 

 has neither the accessory plates nor the tubes, as in Callorhynchus. 

 Necessity for the squirting apparatus is in great measure done away 

 with, since the openings to the spermatic ducts are carried down to 

 the prominence immediately behind the anus, and are thus directly 

 under the grooves by which the liquid is conducted. The extremity 

 of the tubes is surrounded by tissue which during the season of sex- 

 ual congress becomes almost as rigid as cartilage. As the cavities in 

 which the holders lie are under the bifid portions of the penes when in 

 position they may also serve for throwing purposes, since a sudden 

 contraction will send their contents between the parts or into the 

 grooves, that the passage of the liquor might be made more certain. 



The " claspers," really intromittent sexual organs, are articulated 

 to the basal cartilage of the fin. They are differentiations from the 

 fin itself. 1 The muscles for their erection and movement are quite as 

 readily traced in this order as in either the sharks or skates. 



Females, being without the holders, have much less development of 

 the pubic portions of the pelvis than the males. In the position cor- 



1 See Prof. L. Agassiz, Proc. Bost. Soc, xiv, 1871, p. 339, for the uses and homol- 

 ogies of these organs. Compare with J. E. Gray, Cat. Shield Reptiles Brit. Mus., 

 Pt. II., 1872, p. 30. 



