70 



ON THE APPENDICEvS GENITALES (CLASPERS) IN THE SELACHIANS. 



made thicker and, towards the end, enlarged in a clavate manner, when compared with the medial 

 one; the lateral branch in particular is often distallj- much swollen. The dermal teeth are fine, a little 

 bent thorns, all with the points forward, towards the base of the organ. The lateral branch does not 

 contribute to the bordering of the appendix-slit of the terminal part, this slit running onlj- between 

 the medial and the dorsal branch'). 



In three specimens of the respective length of 78'=", 77'^'", and 70^"', the measures were: 



The length of the appendix from the fore edge of the cloaca 7,5'"", 10,5"'", 6,5"° 



The free part of the shaft 2,3™, 2,6"='", 2,3"= 



The terminal part 4,5'="', 6"", 4,1' 



The breadth (on the broadest part of the shaft) 1,1'^'", 1,6'^'", 1,1'= 



The breadth (on the middle) of the terminal part 0,7''"', 1,1"'", 0,7'^ 



The peh'ic copulator^- appendage has in all three specimens a length of . 2,1*^ 

 — — — — -- — — a breadth of 0,6'' 



5 cm 



fcm 



rCin 



I TCin 



tCITI 



^cm 



In one pair of ventrals, kept in spirit, and skeletonized until the terminal part, belonging to a 

 specimen the total length of which I am not able to give, the appendix has had a length of more 

 than 9'^''^, tlie terminal j^art of almost 6''" by a breadth on the middle of 1"='", at the end of 1,5"'"; the 

 skeletonized pelvic appendage is 2™ long, and i'^"' broad. 



The skeleton. The pelvic arch is divided in the middle line, so that it is comi^osed of a 

 right and a left piece; behind, dorsally above the articulation with the ventral, each of these pieces 

 is prolonged to a considerable process; on the foremost convex edge the peculiar, movable, foremost 

 copulatory appendage, the vSageplatte (Gbr.), is articulated; the skeleton of this appendage is com- 

 posed of one piece, the medial edge of which bears a row of (5 — 7) large, crooked, finel\- pointed 

 dermal teeth ; when in rest this piece is turned against the ventral surface of the pelvis which is 

 hollowed like a spoon, and then onh- the toothless edge laterally of the row of teeth is seen in the 

 opening of the pouch. 



The fin-stem consists of a short, flat b as ale B bearing all the rays (the foremost broad mar- 

 ginal ray [R] is coalesced with it) , a l\ , a good-sized /3, and the appendix-stem b ^). 



b^ is not much shorter than the basale, with which it is connected in a rather movable joint; 

 on its medial side it is flat and broad, on the lateral side longitudinally concave; dorsalh' it forms a 

 narrow edge, forward produced into a large process a-, which by a lateral incision is made to form 

 the inner bordering of the above mentioned opening, with which the appendix-slit begins; the other 

 part of the dorsal edge of ^i is somewhat laterally bent, and bears a rather firm margin of connective 

 tissue; the \'entral edge is straight and rounded. 



The piece /9 is tolerably triangular, but with cur\-ed sides; it is much curved, and situated in 



■) In Cliitncera affiiiis Cap. the appendices, according to Goode & Bean (I.e. pi. X, fig. 34, 35), are three-branched 

 as in Ch. monsirosa, but else they seem to differ rather much from those of this latter. The figures, however, are not distinct 

 enough to get a clear notion of the facts. 



2) In the figures of Gegenbaur I.e. pi. XVI, fig. 22, 23, and of v. Davidoff, I.e. pi. XXIX, fig. 19, pi. XXVIII, 



fig. 3, 4. these skeletal pieces are marked in sucli a way that: b^ = ['' ^^^\ ;J = ['' *^''^''' , ^ = '' '^" '-"'^''• 



U' D. U3 D. (C2 D. 



