ON THE APPENDICES GEXITALES (CLASPERS) IX THE SELACHIANS. 



45 



(if)T, 



(u)Tdr. 



\; Tu(e) 



io>Td - 1 y 



gth 



Fig. [5. Heterodontus 

 Phillipi. The skeleton 

 of the right appendage. 

 After G e g e n b a u r 1 1. c. 

 fig. 19), somewhat re- 

 duced. The letters pla- 

 ced in parentheses are 

 those used by Oegen- 

 b a u r. r the last raw 



Notidanidce. > 



Chlamydoselachus anguineus Garman. 



GiintherJ) has briefly described the appendages and their skeleton, 

 and given figures of them. Only a third part of the length of the appen- 

 dages is free of the fin, „as is the case in the Notidanidcs generally", and 

 there is no notch in the hindmost fin-edge, between the membrane and 

 the appendage. Between the basale and the appendix-stem there are « three 

 rudimentary and one larger intermediate cartilages" (b t , b 2 , £ 3 , £,?), none 

 of which bears any ray. To judge by the figure, there is no piece j ; 



The peculiar mixture of Shark-like and Ray-like characters that, as it is well known, is found 

 in Rhina, is accordingly increased by several features in the appendages of the male, which features 

 by the ventral covering piece and the pocket, situated below it, with entrance from a side-slit, and 

 partly also by the glandular bag, recall those in the Rays (Torpedo, Narcinc, Rhinobatus and Trygon\ 

 while most of the other features are those common in other .Sharks. 



Cestraciontidce. 



Heterodontus (Cestracion) Phillipi (Cuv.). 



The skeleton has been described by Gegenbaur 1 ). Between the basale and the appen- 

 dix are found two pieces (b z , b 2 = ft, fj\ I.e. fig. iX, 19) that bear no 

 rays; the piece /? is well developed (1. c. /> fig. 19). The chief piece of 

 the appendix is provided with two (rather long?) marginal cartilages (the 

 boundary lines of which cannot be seen in the figures of Gegenbaur, 

 as he has not understood the marginal cartilages to be particular pieces), 

 of which the ventral one has a dorsally bent plate (I.e. fig. 19, a); the 

 stem is prolonged into a long style reaching almost to the end of the ter- 

 minal part (1. c. fig. iq, 20, /l. The number of terminal pieces is four: Td 

 (=].c. fig. iq, 20,c), Td 2 (== 1. c. «), which, as is often the case, is prox- 

 imally prolonged into the appendix-slit; Tv (= I.e. e), as commonly, 

 stronger and thicker than the others, and finally T forming a short thorn. 

 Gegenbaur has correctly seen the homologies of these pieces with those 

 in Acanthias, where, however, he has not seen the piece Td 2 (= u in 

 Heterodontus). Of these terminal pieces the piece T is said (1. c. S. 452) 

 to be hard, while the others, though fully developed, are still cartilaginous. 



RJ 



i) 





Td 



II) 



Tv 



Fig. [6. Chlan, 



hus anguineus. 

 Tin- skeleton of the 

 right appi 



Attn t '. u 11 t h er. 

 somewhat reduced. 



The letter-, in the 

 parenthes( 



inal ones. 



along the ventral marginal cartilage to the lateral surface of the appendix-stem, we should have a similar state of matte 

 in tikina. There can scarcely be any doubt that the gland in this Shark ami in the Kays in spite of the difference of po- 

 sition — are in reality homologous. Furthermore the glandular bag in younger stages of the Kays seems to pass through a 

 stage of development, in which there is, also as to the exterior, a conspicuous similarity with that of the R/iiua, without any 

 conspicuous longitudinal furrow etc. (see later under Raja batii 



') Uber die Modificationen etc. 1870, p. 450, Taf. XVI, fig. iS — 20. 



-) I regret verv much that my efforts to get ventral fins with developed appendages of Hexanchus \nchus 



have been in vain. The figure of the skeleton of Heptanchus cinereus Ag given by Fritsch in Fauna der Gaskohh 

 Bohmens, vol. 3, 1895, p. 45 is quite useless. From this figure appears only that at least the two terminal pieo '..■' and '/';■ 



are found; what fritsch calls the sporn is the last ray lor rather the two last, coalesced ones). The 1 of the figure, I 

 suppose to be the piece ,;, and it is certainly not the I.et/tes Glied des Hauptstrahles . The figures of the structure of tin- 

 appendages in the extinct Xenacanthidtz , given by Fritsch as well in his chief work as in several articles in the Zoo. 

 zeiger» (888 91, I think to be justified in designating as unreliable; but by means of the published figures alone tl 

 structure cannot be determined. 



9 Voyage of 11. M. S. Challenger, Zool., Vol. XXII, [887, S. 2, Tab. 1,X1\ , fig ■ D, />'. 



