1922.] 



H. A. Baylis and R. Daubney : Parasitic Nematodes. 



279 



portion of its length, and is quite a conspicuous organ. The rather short, oblong 

 ventriculus is less conspicuous, but is not difficult to observe in a well-cleared speci- 

 men. AH these characters, taken together, leave no doubt as to the generic position 

 of the species. 



The characters of the caudal end of the male appear to have been adequately 

 described and figured by Smith, Fox and White, (von Linstovv's material consisted of 

 females only) — with the remarkable omission of any mention of an accessory piece, in 



0-3 mm/. 



Fig. 12. — Porrocaecumreticulatum. Tail of male; lateral view. 

 a. p., accessory piece ; s., right spicule. 



addition to the two spicules. The presence of such a structure in an Ascarid is highly 

 remarkable, yet in the material at our disposal every male possesses a conspicuous 

 accessory piece (fig. 12, a.p.) composed of clear, yellowish-brown chitin. This organ 

 appears smooth, whereas the spicules (which are of a darker colour and are simple, 

 tubular structures, without alae), have a rough, granular appearance. As regards 

 the caudal papilla? of the male, we are in agreement with the description given by 

 the American authors. There are two very small pairs on the finger-like caudal 

 appendage; one large postanal pair just before the constriction of the tail ; and an 

 anterior row in which we have counted five on either side, commencing with a pair 

 at the level of the cloaca. 



The almost spherical eggs, in our specimens, are slightly smaller than the 

 measurements given by the former describers, but this is possibly due to the im- 

 maturity of the females. The egg-shell is pitted externally, as described by the Ameri- 



