URINOGENITAL ORGANS 



cartilage is usually produced into a sharp calcified style, near which 

 terminal pieces are developed (Fig. 88). 



Among the Selachii, Huber distinguishes three main types of 

 modification of some importance in classification. Type A : with 



Fig. 90. 



A, Urinogenital system of the female, B, of the male dogfish (Scyttium). db.p, abdom- 

 inal pores ; cl, cloaca ; cp, claspers of the male ; /, rudiment of the oviducal opening in 

 the male ; Md, metanephric ducts ; mtn, metanephros ; od, oviduct ; oe, cut end of oesophagus ; 

 o.g, oviducal gland ; oo, ovary ; l'.j\ pelvic fins ; 11, rectum ; s.s, sperm-sacs ; T, testis ; u.p, 

 urinary papilla in the female ; ug.p, urogenital papilla in the male ; u.s, urinary sinus ; v.e, vasa 

 .ett'erentia ; v.s, vesicula seminalis ; W.d, Wolffian duct; W.g, Woltlian gland or mesonephros. 

 (After G. C. Bourne.) 



a prominent hard terminal style, piercing the skin ; a tegumentary 

 fold partially covering the groove ; and the whole internal cavity 

 glandular. Type B differs from the former in having the tegu- 

 mentary fold inside, the overlapping edges of the main cartilage 

 more developed and turned in, and the terminal cartilages reaching 

 to or beyond the end of the style. Type C : the gland is 

 specialised and of tubular structure ; and one, two, or three of the 

 accessory pieces form flattened sheathing-plates (Fig. 89). Type A 



