2 9 8 



POLYPTERINI 



and it differs markedly from that of the Elasmobranch. In the 

 sacculus of the membranous labyrinth is found a large solid 



otolith, like that of the Actino- 

 pterygii Holostei. 



The urinogenital organs of 

 the female are normal. Each 

 oviduct opens into the coelom in 

 front, and into the base of the 

 mesonephric duct behind; the 

 ova thus pass to the exterior by a 

 median urinogenital pore behind 

 the anus (Fig. 355). In the male 

 the ducts are more specialised 

 (Budgett [68]). The testis sac 

 passes directly into a tube leading 

 backwards to open into the urinary 

 sinus, formed by the junction of 

 the mesonephric ducts (Fig. 356, 

 C and F). The spermatozoa pass 

 out through the median urino- 

 genital pore without entering the 

 kidney. This separation of the 

 vas deferens from the mesoriephros 

 is probably secondary, and may be 

 considered to have been brought 

 about by the same gradual process 

 as in the Dipnoi (p. 253). The 

 freeing of the vas deferens from 

 the mesonephros, however, is not 

 evidence of any close relationship 

 with the Dipnoi, since it is found 

 to have taken place independently 

 in the Teleostei (p. 366) and in 

 the Amphibia (some Anura). 



Owing to the presence of lobate 

 paired fins, of paired gulars, of 

 rhomboid scales, and of an out- 

 wardly diphycercal tail, and to a 

 considerable similarity in the dis- 

 FIO. 270. position of the roofing cranial 



Alimentary canal of A, Polypterus; and bones, Huxley placed the 

 Anat.) ap, caecum ; c.p, pyloric caeca ; dc, pterini in his Sub-orde 



&&^. < ?.ar l "' Pyl0r " 8; Pterygidae [227]. Comparing the 



living with the fossil genera, the 



resemblance of the paired fins is merely superficial, that of the 

 cranial bones only general; the tail is probably secondarily sym- 



