ON THE APPENDICES GENITALES (CLASPERS) IX THE GREENLAND SHARK. t . 



the question). Consequently I design the large chief muscle .1 as Musculiu 

 pinna (if appendicis\ the muscle E as Muse, extensor {np^riiJias) x ). 



b. The ventral muscular system of the rays (fig. 58, 60, Ra) is composed of distinctly separated 

 bundles of fibres, or independent muscles in number corresponding with the rays they follow; only 

 anteriorly the independence of the ray-muscles, as mentioned above, is concealed by coalescence with 

 the lateral bundles of Muse, adductor, coming from the pelvis. The ray-muscles originate on the 

 ventral surface of the basale and the piece /',, and rim laterally backwards in an oblique direction. 

 each following its ray, but without reaching the end of it; they only reach the horny filaments 

 two layers of which comprise a rather considerable part of the lateral ends .if the rays) and here 

 pass into tendinous tissue. The hindmost ray-muscle is rudimentary; it does not originate 

 the stem-skeleton, but on the last ray but two, and passes to the last but one and on to the fin- 

 membrane. 



2) The dorsal muscular system of the fin proper (pi. V, fig. 59) is composed of a) a su 

 ficial part originating from the lateral muscles of the body, and b) a deeper-lying part originating from 

 the stem-skeleton. 



a) On a part of the body, corresponding in length to the connection between the body and the 

 fin, a system of distinct muscular bundles (C) originate in the aponeurosis covering the lateral muscles 

 of the body, and run obliquely outward and backward to the horny filaments, where they pass into ten- 

 dinous tissue; thus their outward border corresponds to that of the ray-muscles on the ventral side, 

 being considerably distant from the ends of the rays. The hindmost of these bundles are dire 

 straight backwards, corresponding to the direction of the last of the rays. Furthermore from the 

 inner side, the side towards the muscles of the body, of the said system some bundles of fibres 

 originate running obliquely backward and inward, and attached to the hindmost half of the basale 

 and to the dorsal piece f}\ thus the whole system originating from the lateral muscles, is, as to the 

 hinder half, arranged in a feather-like or faushaped way. 



b. Unite covered by the superficial layer just described the deeper layer of the dorsal ray- 

 muscles (fig. 5c), Ra) is found. These muscles originate from the dorso-lateral side of the basale and 

 of the piece />, as well as from ,3, and are seen as distinct bundles corresponding in their number and 

 direction to the rays; they pass into tendinous tissue immediately before the lateral ends of the bundles 

 of the superficial layer, so that the latter reach a little way farther on the rays. However, these 

 two layers are not quite sharply separated, bundles of fibres from the superficial layer : to the 



deeper, and connecting with it; on the hindmost fin-rays the bundles of the deeper layei cross those 

 of the superficial one, this latter spreading in a faushaped way from the attachment to tin 



II. Besides the described separate parts of the fin muscles connected with the appendix 



'I The muscle which in Acanlhias and other Selachians corresponds to tin i b) Petri 



pterygopodii; but there are several objections to this name. Firstly, the muscle d I only act endix, bul 



the whole fin (it is also found in the female), and next it cannot well he called the flexor of the appendix, a- it is n 

 properly to be regarded as the extensor. The flexion of the appendix is, I suppose, effected by means oj 



sacci, the muscle of the glandular bag i lit;. 5S, i.i, ,V i, of which more hereafter, together with tin ting 



on tin- body itself (fig. 59 and 61, O). 



