ON THE APPENDICES GENITALES (CLASPERS) IN THE SELACHIANS. 69 



Chimaera monstrosa L. 



(PI. I, fig. 14. 15; pi- VI, fig. 69-71.) 



The larger part of the appendix 1 ) is free of the fin, and the appearance consequently differs 

 rather much from that of the other Plagiostomes ; this free part is almost as long as the ventral fin 

 itself in its largest extent (from the point where the foremost part of the fin arises from the body, to 

 the end of the much produced lateral corner). The appendix may also here be divided in a shaft and 

 a terminal part; the shaft is thick, short, only about half the length of the terminal part; its inner 

 contour is straight, the outer one very convex, whereby the appendix gets some resemblance to the 

 part of the human leg below the knee, with a very prominent calf. On the dorsal side the appen- 

 dix-slit runs throughout the free part of the length of the shaft; anteriorly it begins already at the 

 connection with the ventral side of the body as a little roundish opening, the circumference of which 

 is partlv supported bv the inner skeleton, and consequently it is only anteriorly a little dilatable; from 

 this opening the slit, bent about in the same manner as the lateral contour of the shaft, runs to the 

 base of the terminal part, where it reaches close to the medial edge, and from here it passes on into 

 the terminal part along this edge. In front, behind the described hole, and posteriorly, where the 

 slit passes into the terminal part, its lips can only with difficulty, or not at all, be opened on account 

 of the stiff inner skeleton, but in the rather long interspace it is easily opened, as the lips are com- 

 posed of soft parts (muscles); in a specimen before me the two concerning, normally tight spots of 

 the slit are closed by the coalescing of the skin; in another specimen the case is the same, only to 

 a less extent, with the right appendix. The skin of the shaft is naked, smooth, thin, and slightly 

 pigmented, so that the muscles and their arrangement can be distinguished rather distinctly through it. 



The long terminal part is composed of three branches 2 ) a medial one (£*) in immediate con- 

 tinuation of the straight medial edge of the stem; a dorsal one (6**), lying quite close to the lateral 

 edge of the foregoing, commonly only separated from it by the very narrow continuation of the appen- 

 dix-slit; in one single instance, however, I find the skin coalesced for a considerable part of this slit, 

 so that these two pieces only towards the point can be separated; finally a lateral branch (6***), rather 

 free of the other two. These three branches are generally of almost equal length ; sometimes the medial 

 one is a trifle longer than the others; they are stiff, and in their whole length supported by skeleton; the 

 medial one is covered with a fine, but firm, thin skin, through which the skeleton is seen very di- 

 stinctly; it is rounded on its inner, medial surface, and ends in a little, swollen knob; the lateral side 

 is flat, and pressed into a furrow in the skin of the dorsal branch. This latter branch and the lateral 

 one are more or less completely wrapped by a soft, loose, and tooth-covered skin, by which they are 



'I The copulatory appendages have been described, more or less completely, by a rather large number of authors, 

 of whom I shall only mention: Gunnerus: Oni Hav-Katten, Det Throndhj. Selsk. Skr., 2, 1763, p. 299, pi. V— VI; Kroyer, 

 I.e. p. 79S seq. Lilljeborg, I.e. p. 51S; Dumeril, I.e. p. 681; Moreau, I.e. p. 463; the descriptions in Gegenbaur I.e. 

 p. 453, and v. David off I.e. p. 453 are very complete. Xojie of these authors mention the glandular bag. 



-) In C/iim. collici Eenu. living in the Pacific Ocean (at the coast of California), the terminal part is said to have 

 only two branches (Dumeril I.e. p. 6Sr, Goode & Bean I.e. p. 32); Bashford Dean (Fishes living and fossil, 1895), gives 

 however, p. 107, fig. 116, a drawing showing three branches, the medial one of which is invested at the point with dermal 

 teeth, and besides by an articulation separated from the other part; this latter fact may perhaps be caused by an acci- 

 dental damage. 



