I Xl'l \\ \TKN .1 II \l I 2C. 



' at the base of 



tin- N '! ,. I ' ' t-- ,,f iirin.il ' ' 'ItlCt 



of the fem.ilc. '</". Mull. Iffian 



duct in the frui.ilc I fig. tf. f> WA -. I'nn. 



'In- md "f a .gnu-tit. d tube to join the collecting tube of the preceding 



vl tul)c. ru. Ureter commencing to be for 1 1 



>eminal bladder, s </. Segmental dm t. f /. Segmental tulxs. // o. Opening of 

 H'lital mix- into body-cavity. >///-. Supi.t; . /. Testis. u. Ureters, 



rens. wb. Woli'ibn : 



1 ' I \ II- 20. 



Fig. i. Diagrammatic representation of excretory organs on one side of a male 

 Scyllium. canicula, natural size. 



Fig. i. Diagrammatic representation of the kidney proper on one side of a female 

 Scyllium canicula, natural size, shewing the ducts of the kidney and the dilated por- 

 tion of the Wolffian duct. 



Fig. 3- Opening of the ureters into the Wolffian duct of a female Scyllium 

 canicula. The figure represents the Wolffian ducts i7,-</) with ventral portion removed 

 so as to expose their inner surface, and shews the junction of the two \V. ducts to 

 form the common urinal cloaca, the single external opening of this (o), and openings 

 of ureters into one Wolffian duct (ou}. 



Fig. 4. Anterior extremity of Wolffian body of a young male Scyllium canicula 

 shewing the vasa efferentia and their connection with the kidneys and the testis. The 

 vasa efferentia and longitudinal canal are coloured to render them distinct. They are 

 intended to be continuous with the uncoloured coils of the Wolffian body, though this 

 connection has not been very successfully rendered by the artist. 



Fig. 5. Part of the Wolffian body of a nearly ripe male embryo of Scyllium 

 canicula as a transparent object. Zeiss a a, ocul. 3. The figure shews two segmental 

 tubes opening into the body-cavity and connected with a primary Malpighian body, 

 and also, by a fibrous connection, with a secondary Malpighian body of the preceding 

 segment. It also shews one segmental tube (rst) imperfectly connected with the 

 accessory Malpighian body of the preceding segment of the kidney. The coils of the 

 kidney are represented somewhat diagrammatically. 



Fig. 6. Vasa efferentia of a male embryo of Scyllium canicula eight centimetres 

 in length. Zeiss a a, ocul. 2. 



There are seen to be at the least six and possibly seven distinct vasa going to as 

 many segments of the Wolffian body and connected \sith a longitudinal canal in the 

 base of the testis. They were probably also connected with a longitudinal canal in 

 the Wolffian body, but this could not be clearly made out. 



Fig. 7. The anterior four vasa efferentia of a nearly ri|>c embryo. Connected 

 with the foremost one is seen a body which looks like the remnant of a segmental 

 tube and its opening (rst?). 



Fig. 8. Testis and anterior part of Wolfiian body of an embryo of Squatina 



vulgarU. 



The figure is intended to illustrate th; the vasa efTercntia. There 



