GARMAN: the CIIIMAEROIDS. 251 



The Clampers, Plate 3, Figures 1, 4, 5. 



The claspors of Rliinochimaera are similar in construction to those of Callo- 

 rhvnc'hus; they differ greatly from those of Chimaera. They have the ap- 

 pearance of beinii formed of a narrow strip of cartilage rolled into a tube, then 

 twisted so that the joined edges, indicated externally by a shallow groove, are 

 given a complete turn in the length of each clasper. In the distal half each is 

 rmmd, hard, and slender; proximally each is much thickened by the strong 

 m'lscles that surround its base and include the receptaculum, the opening to 

 which is hardly visible on the outside. At the free end, the tube from the re- 

 ceptaculum opens in the cleft extending from the interior of a small, fleshy, 

 spine-covered bulb. As the claspers lie at rest, the clefts open outward from 

 one another ; but when in function the claspers are turned down and forward 

 with a slight rolling motion, Plate 3, Figure 4, making the clefts to open 

 inward, more toward one another, and the spine-covered surfaces to be carried 

 outward so as not to come in contact. The spines at the extremities are erec- 

 tile and hook toward the bases of the organs, thus forming effective holders. 

 Turning the claspers down and forward from the body ajjpears to open the 

 mouths of the receptactila and bring them near the openings of the spermatic 

 ducts. For comparison with those of Rliinochimaera the intromit tent organs 

 of a skate, Raia laevis, are figured on Plate 4, Figure 5 ; they are turned toward 

 the head as in function, without indicating the peculiar structures of the carti- 

 lages near the outer ends. The position of the clasper with regard to the ven- 

 tral fin may be a matter of no great importance, yet it adds to the number of 

 peculiarities distinguishing recent Chimaeroids from the Plagiostomes. The 

 clasper of the Chimaeroid, Plate 3, Figures 1 and 2, occujjies a position above 

 the edge of the ventral fin. in a measure between the fin and the body ; that of 

 the Plagiostome (Plate 3, Figure 3, a young specimen of C'archarinus terrae- 

 novae) lies below the edge of the fin, which extends between the clamper and 

 the body. 



The Skull, Plate 1, Fig. 2. 



In the skull of Rliinochimaera pacifica there is little or no departure from 

 the general type of Chimaeroid skull. The shapes .as outlined, either from 

 above, below, or from the side, may be described in similar terms, and the 

 minor differences are not much greater tlmn are to be seen in the different 

 species of Chimaerae, or even than those obtaining in the different stages of 

 an individual of a species of Callorhynchus. The parietal region is broader 

 than that of Chimaera monstrosa, and narrower than that of Callorhynchus 

 callorhynchus ; the frontal region is thicker, wider, 'and rounder, and does not 

 form a blade- like crest as in Callorhynchus. The facial portion, oral and 

 olfactory section, is more jiroduced than that of Chimaera monstrosa; in this 

 respect it more resembles that of Callorhynchus callorhynchus, in which the 

 narial portion of the skull is much farther forward from the eye than in Chi- 

 maera monstrosa, Plate 11. In the young of Callorhynchus callorhynchus, 



