Dr. L, Orley on Nematodes. 



309 



For the Polymyurii Sclineider enumerates ten genera, of 

 which Enoplus is not to be regarded as rightly pLiced among 

 them, and the genus Ceratosjyira is not represented in the 

 collection. On the other hand, I add to the group the genus 

 Spiroptera^ lately characterized by Linstow, and the genus 

 Agamonema as an appendix, which contains young forms of 

 Ascarts, and probably of other genera. For this reason 

 Agamonema is not, strictly speaking, a genus at all, but 

 merely a collector's name for various young stages of Nematen- 

 tozoa. Thus we have ten genera of Polymyarii represented in 

 the collection. 



A. Polymyarii, Schn. 



I. Genus AscARis, Rud. 



Mouth provided v/ith two lips ; two spicula of similar form ; 

 prgeanal papillae to the number of twenty and upwards. 



The species are arranged according to the systematic posi- 

 tions of the hosts. 



* Specimens of different races. 



t Has been considered the young stage of A. dcpresso, Rud. 



X From Arctartic region. 



Ann. & Mag. N, Hist. Ser. 5. Vol. ix. 22 



