ON THE APPENDICE.S GENITALES (CLASPERS) IN THE SELACHIANS. 33 



what conicalh- tapering, on the greater part of the surface covered with dermal teeth; only immediately 

 at the cloaca the dorsal side is naked, as is also the outermost point of the appendix, which is soft and 

 papillous; from here a naked, depressed stripe reaches forward on the medial side of the terminal 

 part'). On this part the dei^mal teeth have another shape than elsewhere on the animal, being longer 

 and more pointed, like small thorns with the points turned towards the base of the appendix; 

 accordingly the hinder part of this is rough to the feeling when rubbed backward, contrary to what 

 is the case elsewhere on the animal. The appendix-slit is covered in the terminal part hv a thin, 

 soft membrane arising from the dorsal (inner) lip; when this membrane is thrown back, the furrow 

 is found to be open as usual; but above the terminal part it is only represented bv a groove in the 

 skin, not very deep; the slit, which in the Sharks, hitherto mentioned, is quite open, is in this animal 

 under the dermal furrow by coalescing formed into a tube reaching to the base of the organ near 

 the cloaca, and first here an opening is again found, an oval aperture through which a sound may 

 be brought into the glandular bag. This latter accordingly has two outlets, one at the base of the 

 appendix, the other between the movable parts of the terminal part-). 



The skeleton. Between the basale and the appendix is found one very small piece (/;,) 

 bearing no rays; the piece /3 is also inconspicuous, somewhat triangular, with a broad articulation 

 before with the basale, a narrow one behind with the appendix-stem. 



The appendix-stem is of about the same length as the basale; it is calcified to a rather 

 considerable degree; the soft end-st)-le reaches to somewhat more than half the length of the 

 terminal part. 



Both marginal cartilages are specially strongly and peculiarly developed, which will be seen from 

 fig. 16 clearer than from a description. The dorsal one {Ri/) reaches (as is usual) somewhat further 

 forward than the ventral one, but in the dorsal middle line it joins with the latter for a long wav by 

 a firm suture , so that the two cartilages together with the stem form a complete, firm tube, open 

 before where the glandular bag joins it, and behind at the terminal part. Thus the part of the ventral 

 marginal cartilage assisting in the forming of this tube, corresponds to the folded plate of the ventral 

 marginal cartilage in the before mentioned Sharks 3). 



The number of terminal pieces is four 4), completely corresponding to those in Acanthias. 

 Td is narrow, somewhat triangular; along the side towards the furrow it is connected with a thin, 

 style-shaped piece, Td, which proximally becomes broader, and reaches a little under the dorsal mar- 

 ginal cartilage. Tv is broader, lengthened-oval, rounded on the outer side, towards the furrow slightly 

 hollow, thick, and solid. Between its proximal end and the ventral marginal cartilage is inserted a 

 well developed piece, 71, which is not formed as a thorn, nor can it be erected to such a position, as 



') At X in the fig. 6 of Petri. 



2 Davy, J.: On the Male Organs of some Cartilaginous Fishes, Phil. Tr. vol. 10, 1839, p. 146, has already mentioned 

 this fact in Scylliutn Edwardsii; Petri represents it I.e. p. 304. 



3) As Petri has not seen the marginal cartilages as such in Acanthias , he has in Scyllitim understood them to be 

 something particular in this genus. 



4J When Petri also finds four pieces in Scy//itim it arises from his counting the end-style of the stem (6'" fig. 7, C); 

 he has really overlooked one piece, viz. 7V2. 



The Ingolf-lixpeciition. II. 2. 5 



