56 ox THE APPENDICES GENITALES (CLASPERS) IN THE SELACHIANS. 



part, and the firm body of the spoon part of the terminal piece Z, is intercalated as a kind of ar- 

 ticnlar head (see fig. 55). 



This latter, T,, is large, forms a half-moon-shaped plate (fig. 55), the distal horn of 

 which is bent in a somewhat hook-shaped manner; the proximal horn stretches in between the mar- 

 ginal cartilages, far forward in the appendix-slit; on the concave edge of the half-moon the mentioned 

 articnlar head)') projects bearing a large, transverse-oblong - articnlar surface ; the upper or inner 

 surface (the surface towards the appendix-slit) bears at the lateral, convex edge a thin, bent, sharp 

 ridge which in some individuals is undulating or fineh- indented; it is the above mentioned edge 

 seen on the undamaged organ 2). 



Still has to be mentioned a peciiliarly elevated, round, narrow cartilaginous ridge .r, running 

 across the dorsal surface of the appendix-style; this ridge seems to me only to be a special swelling 

 of the style, and to correspond to the calcified and thickened bump x in R. baf/s and clavata. 



Raja fyllae Ltk. 



In a specimens) of a total length of 55*-''", a breadth of 30,5'^™, the fully developed appendices 

 are 11"" long, i.e. exactly '/j of the total length. 

 The other measures were: 



rCin 



rem 



From the beginning of the slit to the end of the appendix .... 9=™ 



The part free of the fin 7,6^'" 



The length of the tei'minal part 5,5"^'" 



The breadth across the shaft 1,5'= 



— — — the terminal part 1,75"^ 



As in the other Rajtr the appendix is naked. The outer form as well as the inner configura- 

 tion of the appendix-slit in the terminal part is very much like that of the Skate. The contour con- 

 sequently is of a more slender club-shape than in R. clavata or radiafa with a longer shaft and a 

 pointed-ovate, somewhat broader club constituting the larger, hinder portion of the terminal part. As 

 in the Skate the appendix-.slit can be seen for its whole length from the dorsal side, but runs close 



' I This evidenth- corresponds to the tap on the piece T'j in the Skate, which overlaps the piece Tv2. 



2) B 1 o c h I.e. pi. IX has drawn most of these terminal pieces in a very recognizable manner , some of them even 

 excellently (as fig. 4 and fig. 5). He distinguishes between an upper part (the chief piece of the appendix), and a nether part 

 (the terminal part); the first he interprets as a tibia with its fibula (?J (<'.ein Rohrenknochen , und sitzet letzterer oberwarts, 

 wie bey anderen Thieren , an dem Schienbein fest); this latter is ^ my dorsal marginal cartilage; I.e. fig. i and 3, q\ the 

 tibia again consists of: a piece (= my ventral marginal cartilage), 1. c. fig. i and 3, r, r, welcher unter gewissen Umstanden 

 die Rinne verschliest , and of an ; unterer Knorpel> (^ my appendix-stem), fig. 3, j; it ends hooklike; this is brought about 

 by the fact that Bloch has not separated the covering piece d^ from its connection with the st^'Ie. Bloch makes the nether 

 part consist of five pieces, which number arises from the fact that twice he makes two pieces one. These five pieces have the 

 following relations to my appellations: 



T; = fig. 4, < der Sichel >. 

 Tv2 = - 5, der Helm>. 

 7\i = - 6, der wurmformige Knochen . 

 Td -L Td2 = - 7, der Winkelhaken . 

 d^-^d.— - S, 'die Schaufel . 



3) Station 25, at a depth of 5S2 fathoms; the Davis Strait. 



