ON THE APPENDICES GENITALES (CLASPERS) IN THE SELACHIANS. 



shape to the medial side; to the lip / which in the Scyllia is turned into the furrow, corn 



the part in Pristiurus marked with the same letter, to the naked dermal fold i in one corresponds the 



naked dermal fold i in the other, etc. 



Also the skeleton shows the near relation to the other Scylliidce. Between tin- basale and 

 the appendix is found (ventrally) a very small, quite rudimentary piece b l which of course bears no 

 ray; dorsally is found an also very small piece j. 



The appendix-stem and the marginal cartilages are much like those in the Scyllia. The 

 stem is twisted longitudinally in a similar manner as in Sc. stellate , hut is not bent medially. The 

 dorsal connection of the marginal cartilages, however, is not so close as in the Scyllia; the two 

 pieces may here be forced a little from each other. 



The number of terminal pieces is five, if to the terminal pieces we will count a piece, AV,, 

 which has not been found in any of the Sharks, mentioned in the foregoing; it is joined movably to 

 the hindmost edge of the dorsal marginal cartilage, and is situated in the dermal fold below the 

 asterisk in fig, 9. 



Td and Tv are long and narrow, and form at the end of the style a similar kneeshaped curve 

 as in Scyllium stellare (in Sc. canicula it is only indicated); a slightly calcified or almost quite soft 

 piece Td, is found, projecting forward under the edge of AV; Tv proximally forms a rather broad 

 plate, to the dorsal edge of which is attached a leaf-shaped, somewhat bent piece T. All the pieces 

 are completely hidden in the skin. 



The muscular system is substantially quite the same as in the Scyllia, the only 

 difference being that the outer lip-muscle seems to lie still less developed in Pristiurus. 



Lamnidce. 



Lamna cornubica (Gmelin). 



(PL II, fig. 22, 23.) 



In a specimen of the length of 2 ,n 5"", which in the beginning of November [897 was driven 

 on shore on the western coast of Jutland, the appendix has a length of 2i cmI ) and a largest breadth 

 of 4 cm ; the terminal part is 7,5"" long. The whole ventral surface is densely covered with dermal 

 teeth quite to the end; this investment ceases with a strongly marked boundary line on the medial 

 surface, which is quite naked to the terminal part; this latter being almost quite covered with teeth 

 until the margins of the appendix-slit, also on the dorsal side; the other parts of the flat dorsal side 

 of the shaft are naked, and these naked parts are laterally marked off from those covered with teeth 

 by a rather deep longitudinal dermal fold. Apparently the appendix-slit from before the terminal part 

 and to a larger foremost opening at the base of the appendix is closed as in the S : but in 



reality it is open, and for the whole way it is possible, though with difficulty, to press a sufficientl) 

 thin sound in between the margins of the marginal cartilages. < >n the medial side, immediatel) 1 



1 Lilljeborg 1. c. p. '125 gives for a specimen of the length of 2.1" a length of 2 idix. 



