64 



ON THE APPENDICES GENITALES (CLASPERS) IN THE SELACHIANS. 



Two pairs of ventrals with fully developed appendices, now before me (unfortunately I cannot 

 give the total length of the animals) show the following measures: 



Length of the appendix io cm 



- part free of the fin 6,2 tm 



- terminal part 4,6 — 5"" 



Breadth of the 2,7 cm at the broadest spot 



- basal part i,6 cm 



A dried specimen of a length of 39°'", a breadth of 24 cm shows fully developed appendices, 

 gem long, and 2,2 cm broad across the terminal parts; in another specimen (in spirit) 43 cm long, and 2o. cm 

 broad the appendices are only 6,5 cm long, the terminal part abt. 4 cm long, 2,i cm broad; here they are 

 not yet fully developed though it was to be expected judging from the size of the animal. Facts as 

 these, that rather grown individuals have rather undeveloped appendices, I have ofteuer seen, for inst. 

 in Acaiifhias. 



The appendix is naked, much more clumsy than in the 

 preceding species, flattened, somewhat rounded on the dorsal side, 

 the contour is clumsily clubshaped; the club is formed by the 

 terminal part constituting more than half the length of the part 

 to be seen from the back. The appendix-slit runs from the fore- 

 most dorsal opening laterally, so that it cannot be seen from the 

 dorsal side except in the hindmost end of the terminal part, 

 d I \ where the dorsal lip, as it were, retires; the dorsal lip, throughout 



AF the terminal part, is supported by inner skeletal parts reaching 



-fa ... 



Rd- "flllt. V'V J t to its edge, while the soft membrane of the ventral lip as a broad 



id- •■ ^fm J ~\ J . . . 



vv y /,i wall stretches past its skeletal part (7\), and is laid - in a 



"\ ^t;' ! '' '/■'/ ' ll similar manner as in the Skate - - dorsally against the upper 



fV ; ;J'; ; ■'-/ — bl 



lip; from the hinder, lateral edge of this latter a naked spine 



projects. If the soft, ventral dermal lip vl is thrown back, an 

 T°z £ v elevated, long, bowshaped, cutting edge of the skeletal piece T, 



pj 26 is laid bare (fig. 26 in the text, to the right of bl). If the term- 



inal parts are opened still more (which here is easily done), we 

 Raja radiala. The terminal part of the 

 right ventral, much dilated; reduced. Td 2 shall, although with altered shapes and relations, see correspond- 



the naked spine of this same skeletal j projections and hollows as those described in A', batis and 



piece. The letters as in fig. 24 and 25. 



clavata. The upper side of the piece T 3 does not here show (or 



shows a-t most weak traces of) the transverse folds /;/, peculiar in those two species; a broadly tongue- 

 shaped, rather soft and movable lamella with porous edge and > spongy > lateral surface represents 

 tin in the Skate and the Thorn-back; a large, ovate, hard swelling corresponds to the process Tv,\ 

 behind and laterally of this the ventral recess Li< is found, large and deep; the foremost recess Ld is 

 smaller and more hidden, situated before the ovate swelling, and also the lamella Rd' supporting its 

 lateral wall, is only little conspicuous. 



