ON THE APPENDICES GENITALES (CLASPERS t.\ THE SELACHIANS. 



Tlie skeleton. Between the basale 1 ) and the appendix-stem, as in all Zvto/'o-species, are found 

 a /',, a & 2 , and a ft 2 ); dj also here bears the last six rays. The appendix-stem is about twice as long 

 as B 4- & t -f- # 2 , flattened especially distally; its terminal part, being as usual uncalcified, here forms 

 an s-shaped, quite thin, flat style broadening towards the end. As in the other Raja-species the 

 dorsal marginal cartilage stretches forward almost to the beginning of the stem, but backward not so 

 far as the ventral one; this latter, especially distally, is a good deal broader. To the inner sidi 

 the dorsal marginal cartilage, at its distal edge, is articulajted a triangular cartilage Rd' (fig. 56); it 

 is quite corresponding to the one marked Rd' in the two other /fa/a-species , in which, however, it is 

 only a direct prolongation, a process, from the marginal cartilage itself. 



The number of terminal pieces is five, exclusive of the covering pieces. Three covering p : 

 a?!, <A, d s are found on the dorsal side. The lateral one, d z , is a good-sized, externally rounded 

 plate, with a bow-shaped, convex lateral edge folding round to the ventral side. Its medial edge is 

 rather straight and firmly connected with d 2 , which latter as a narrow band runs obliquely across the 

 terminal part, and tapers towards the medial end that is bent round to the ventral side, and by a li 

 ment attached to the point of the piece T, (see fig. 55). The third covering piece, d 3 , is connected 

 with the lateral end of the preceding one; it is of a triangular, externally somewhat rounded sha 

 and bv a ligament attached to the hindmost end of the appendix-style; with its inner surfat 

 connected with the dorsal side of the piece Td 2 . The three mentioned covering pieces have all an 

 from the same aponeurosis of the M. dilatator, and accordingly they together represent Un- 

 covering piece d iir the Skate and the Thorn-back. 



Of real terminal pieces two are found in the dorsal lip: Td and Td, (see fig. 54, 55). Td is 

 short; it is with its whole fore edge attached to the dorsal marginal cartilage, with it- foremost 

 medial corner also to the appendix-stem; from its medial-distal corner it sends forth a soli, cartilagi- 

 nous part which farther backward is coalesced with the style (comp. the Skate); else its disl 

 is connected with 7V, < a proximallv broad, distally narrow and tapering, very hard, somewhat s-shaped 

 cartilage; it is outwardly rounded, inwardly concave, and ends in the above mentioned thorn projecting 

 naked from under the edge of the dorsal lip. 



To the ventral side belong three terminal pieces: Tv, Tv 2 , and T.. The two first of these 

 are very peculiar, and can only be rightly seen when the skeletal parts are disunited (see fig. 



Tv consists of two parts, a body and a long process; the bod}' is proximallv atta 

 the edge of the ventral marginal cartilage, with one edge to the medial edge of the style (see fig. 

 and with the opposite one to the piece Tv z \ from the ventral surface of the body the process arises, 

 and forms together with the body a kind ofT; this process is bent in an irregularly s-sha] nuer, 



ends in a fine, hook-shaped thorn, and is situated in the deep, spoonlike hollow formed by the pi 



Tv 2 is still more peculiar; its chief part forms an oval spoon, outward! . in- 



wardly very deeply hollowed, from the foremost part of which a large, half-moon-shaped 1 

 ing the inside of the ventral marginal cartilage of the appendix-stem; the lateral edge of the spoon 

 is prolonged into a not quite calcified, winglike process; between this ;, the hi ped 



■i Bloch 1. c: der erste Knochen des Schenkels , fi.n'. r, /. 



2) /,, — tier zweite , 6 2 = • der dritte , ,i = der vierte Knochen di Schenl 



The Ingolf-Expedition. [I, 2. 



