512 MR. T. H. BURLEND ON THE UROGENITAL [Mar. 1, 



the median zone is Leyrlig's gland, and the caudal zone alone is 

 excretory in the adult male. The author emphasizes the primitive 

 nature of the kidney on account of its marked metamerism, and 

 apparently believes that the sexual portion of the Selachian 

 kidney is absent. 



Bashford Dean (1906) does not recognise any "Geschlechtsniere." 

 W. K Parker and T. H. Burlend (1909) show the relation 

 between vasa efferentia and sperm-duct, the former uniting to 

 give a longitudinal duct which is directly continuous with the 

 coiled sperm-duct, so that the sexual part of the kidney or 

 " Geschlechtsniere" is represented in the adult male by the " rete 

 testis." Attention is also directed to the unsatisfactory use of the 

 term " epididymis." 



Material and Observations. 



I am indebted to Mr. J. J. Neale of Cardiff for much valuable 

 material. The Chimeras, both young and adult, male and female, 

 had been carefully packed in ice and arrived at the laboratory in 

 excellent condition. The alimentary canal having been removed, 

 the whole urogenital region was fixed in corrosive sublimate, 

 90 per cent, alcohol or 5 per cent, formalin ; but the first of these 

 reagents proved the most satisfactory for histological work, the 

 formalin-preserved specimens being most suitable for dissection. 

 Many of the regions were sectioned, and this was especially 

 difficult in the coiled sperm-duct region owing to the slow rate of 

 penetration by the successive reagents. Weigert's Hematoxylin 

 A\ T as used for staining in bulk, and Delafield's or Ehrlich's acid 

 Hematoxylin for staining on the slide ; the Cambridge rocking 

 microtome wa,s used in sectioning. 



Adult male Chimjura monstrosa. 

 Genital organs. 



(a) Claspers. — The anterior clasper, three-quarters of an inch 

 in length, is situated on the head in the dorsal middle line a short 

 distance behind the snout. It is a spherical knob-like organ 

 bearing recurved spines ventrally, borne on a short thick stalk 

 directed forwards ; the whole organ is capable of being depressed 

 into a shallow pit immediately in front of it and so of becoming 

 less conspicuous. 



The middle claspers are wing-like structures practically hidden 

 away in pouches situated at the anterior limit of the pelvic-fin 

 skeleton. In the extended condition they are seen to have 

 cartilaginous supports bearing a row of from 5-7 forwardly pro- 

 jecting spines on the edge nearest the ventral middle line. In 

 text-fig. 40 the left middle clasper is shown everted, m.cl., the 

 clasper on the right side being indicated in the normal position. 



The posterior paired claspers, situated behind the anus and on 

 each side of the urogenital aperture, are stout rod-like structures, 



