o.\ Till'! AI-I-HNDIU-S CKNITALES (CLASPERS) IN THE GREENLAND SHARK. 



which it forms an — to be sure very obtu.se angle. In a fully developed skeleton the chief piece is 

 longer than the basale; in the largest specimens at hand the ratio is: — = c. ; ; on the medial 

 side it is rounded, in the foremost third part somewhat dorso-ventrally flattened; the lateral sur- 

 face (/) is more or less distinctly bounded from the other surfaces; it is only in the fore p 

 somewhat rounded, posteriorly it is flattened, and the hindmost part is somewhat hollow; on the dorsal 

 side this lateral surface is in the whole length of the piece sharply limited by a thin, elevated, hard 

 calcified ridge (fig. 2, 3, Rd), anteriorly beginning as quite low, posteriori) becoming higher and higl 

 as well as thicker, and bearing in the posterior half an edge, folded to the dorsal side, [irregularly 

 indented, and collarlike; on the ventral side (see fig. 3) the lateral surface is in the greater part oi its 

 extent much more indistinctly bounded by an evenly rounded eminence, which is not harder than 

 the common surface; in the posterior part, however, rises rather suddenly a short, calcified, stn 

 ridge or plate, which in the shape of a large foliaceous process folds over to the dorsal side, where 

 it approaches rather near to the opposite edge (fig. 2, 3, Rv). The free edge of this folded process 

 is thickened, and irregularly rugged. The described elevated ridges or plates in connection with the 

 flatly hollowed hindmost part of the lateral surface forms the place of part of the appendix-slit or 

 the excretory duct of the gland-bag; these hard parts of the skeleton it is, that, as mentioned on 

 p. 7, prevent a distension of the appendix-slit. 



Immediately behind the end of these calcified ridges the chief piece continues as a thin, round, 

 finger-shaped elongation, the end-style (fig. 1, 2, 3, g)\ it is soft, or at all events at its base quite 

 devoid of calcification, while farther out a slight surface-calcification may be found. Else the chief 

 piece is evervwhere calcified on the surface (being anteriorly somewhat rough for the attachment of 

 the muscles), and more calcified than the basale and the rays, but the above mentioned ride 

 (Rd, R7<) are completely calcified and hard. When such a chief piece is dried, these ridges 

 therefore will not shrink, but rise distinctly as independent parts. By a close examination of an 

 uudried chief piece the boundary lines of these calcified side-parts may also lie distinguished, and thus 

 we shall arrive at the same result: the chief piece is composed of three parts, viz. the 

 appendix-stem (/'), posteriorly becoming lanceolate, medio-laterally compressed, and ending as a 

 slender, thin, (at the base) uncalcified end-style, and two calcified marginal cartilages, one 1 

 slender, dorsal, the other shorter, broader, ventral (Rd, Rv). 



To this chief piece are attached a number of terminal pieces, more or less movably joined 

 to each other and to the chief piece. Of these pieces two join the posterior borders of the marginal 

 tilages and the end-style of the stem, and form, as a kind of continuation of the marginal cartilages, the 

 dorsal (dorso-medial), and ventral (ventro-lateral) borders of the hinder part of the appendix-slit; these 

 two pieces are here called respectively the dorsal and the ventral terminal piece (Td, 



The dorsal piece (fig.i Td, fig. 4, 5) is the smaller one; it tapers to both ends, most to the post- 

 erior; on the exterior (medially) it is somewhat rounded, with a sharp lateral edge, a little denticul 

 towards the appendix-slit slightly hollow in the foremost two third parts; the thick medial edge is 

 by means of connective tissue closely connected with the end-style, the anterior end with the dors 

 marginal cartilage. It is completely calcified, and the surface, especially towards the terminal end, 1 

 rugged and rough. 



The [ngoIf-Expedition. II. 2. 



