ON THE APPENDICES GENITALES (CLASPERS) IN THE SELACHIANS. 



39 



is a rather thick lamella only partly calcified. Also a piece Tv^ is indicated as a pretty long, thin 

 lamella, which does not calcify or only calcifies to a very small degree (see fig. lo in the text); it is 

 connected with the proximal end of Zt', stretches forward inside the thorn , and is with the anterior 

 end firmly united with the aponeurosis, on whicli the outer lip-muscle-, bespoken afterwards, acts; 

 b\- the pulling of this muscle at Tr-, and Tt' the dilated terminal part is brought back, and the thorn 

 T'j situated between the two said pieces is laid. 7', has more particularly the form of a claw, whose 

 proximal part is head-shaped and rather soft, wrapped in the soft tissue connecting it with the adjoin- 

 ing pieces. 



The muscular system. "YYv^ Ai. adductor \% distally not sharply separated from the J/. fl'//(7/'c?/'(7;-, 

 as part of the fibres of the former passes into the superficial medial layer of the latter. The former 

 mtiscle is quite woven together with the M. cxfciisor, so that it is only by preparing from the dorsal 

 side far into the large, proximal muscular mass that a considerable portion of fibres is found, origin- 

 ating from the basale, and ha\'ing a direction common in the J/ extensor. 



The bag-shaped part of the J/, compressor is very long and rather thick; in the specimen 

 examined b}- me, it is about 40'-''" long, of which 23''" are situated under the ventral skin before the 

 pelvis'). The outer lip-muscle shows the jjeculiarity that in spite of the long ventral marginal car- 

 tilage it is prolonged covering the dorsal surface of the said cartilage until the terminal part, where 

 it acts on Tv by means of the above mentioned lamellar indication of a Tv, in a similar manner, as 

 this muscle acts in Sharks with a short ventral marginal cartilage. 



The J/ dilatator only covers a very small part of the dorsal side of the appendix-shaft, by far 

 the greater part of the dorsal marginal cartilage being covered only by the skin. 



Selachus maxinius (Gunnerus). 



The appendix has been briefly mentioned by Sir Everard Ho me 2), somewhat more detailed 

 by Blain ville3), but not originally by Pavesi-i), whose specimen, however, was a male; only in 

 his second paper^) does Pavesi briefly describe and draw (p. 353) the (undeveloped) appendix, and 

 collects the whole literature treating of these organs, giving also in a table (1. c. p. 406) the dimensions 

 that may be put together according to the obtained facts. The image of the appendix that is to be 

 got from the literature, is upon the whole only imperfect. I have not found any particular mentioning 



' ) The glandular bag contained onh- a little mucus, while the tube of the appendix, and the above mentioned pocket 

 as well as the inside of the terminal part were all filled with an extremely viscid, milk-white mucus, which made the fingers 

 exceedingly slippen- and was difficult to get washed off; it contained numerous ceUs of different size and shape, with oval 

 or round nuclei staining very readily. 



2) i) An anatomical .\ccount of the Squalus maxinius etc. Phil. Trans., 1809, S. 207. 2) Additions to an Account etc. 

 Phil. Tr., 1813, S. 230. Among other things tlie glandular bag is here mentioned as a cavity between the skin and muscles 

 of the abdomen, eleven feet long and two wide. The inner surface of this cavity is smooth, almost polished, and of a 

 beautiful white colour; it contained a white mucus, extremely viscid and tenacious.* 



i) Memoire sur le Squale Pelerin. Ann. du Museum d'Hist. Nat, T. 18, 181 1. 



4) Contribuzione alia storia naturale del Genere Selache. Ann. del Mus. Ci^nco di Genova, vol. 6, 1874. 



5) Seconda Contribuzione alia Jlorfologia e Sistematica dei Selachi. Ann. del Mus. Ci\'ico, vol. 12, 187S. Besides 

 the drawings quoted here one more drawing is found, only, however, a sketched outline, of e\-idently undeveloped appendices 

 of a 'Squalus maximus*, in Carus und Otto: Erlauterungstafeln zur vcrgl. Anatomic. Part 5, pi. V, fig. VIII, 1840. 



