AHT. 21 A NEW AMIDOSTOMINE WORM WETZEL ' 7 



4. The nerve ring surrounds the esophagus at a distance of about 

 300^ from the head end, while in E. skrjabini Petrow gives the dis- 

 tance as 0.0507 mm.; even if, as I suspect, 0.0507 mm. must be con- 

 sidered as a printer's error, 0.507 mm. would still be an important 

 difference from the corresponding figure in E. crami. 



There is some confusion in the literature regarding the terms epau- 

 letlike formations or festoons. Both terms are used by Skrjabin to 

 signify the flaplike ornaments on the surface of the head in E. uncina- 

 timi. Seurat, however, used the term festoon for the lateral cuticular 

 expansions of the head in E. orispimmi, while Petrow calls a cor- 

 responding formation in E. skrjabini an epaulet. By studying front- 

 end views it is clearly seen that the epauletlike formations or festoons 

 of Skrjabin in E. uncinatuTn (Seurat calls them " nodules ") are iden- 

 tical in every respect with the conelike formations of E. skrjahini, E. 

 crarm, and E. orispinrnin (designated as "aiguillons" by Seurat in 

 this last species). The festoons of Seurat in E. orispinum and the 

 epaulets of Petrow in E. skrjabini, however, correspond to the forma- 

 tions called headplates in E. o^anni by the present writer, in order to 

 avoid the confusing terms epaulet and festoon. 



Further it is said by Seurat in his generic diagnosis that the head 

 bears a pair of lateral papillae on each side. The front-end views, 

 both of E. uncinatuni and E. crami, however, show only one exceed- 

 ingly well -developed and prominent lateral papilla or amphid on 

 each side. Regarding the buccal capsule, which is lacking according 

 to Skrjabin or short and reduced according to Seurat, the present 

 writer agrees with Skrjabin. There is no buccal capsule in either 

 species described here. The mouth opening leads into a short funnel- 

 shaped mouth cavity, supported near the mouth opening by the four 

 toothlike formations and communicating posteriorly with the 

 esophagus. 



A further characteristic, not mentioned in the generic diagnosis, is 

 the highly developed striation giving the neck region a typical 

 wrinkled appearance. In order to bring the generic diagnosis of 

 Epomidiostomum in accordance with these facts and to simplify it 

 the following emendation is proposed: "Cuticle thick and trans- 

 versely striated, striations highly developed in the neck region. Head 

 distinct, provided with a special cuticular expansion forming two 

 lateral, one dorsal and one ventral headplates. The front surface 

 bears dorsally as well as ventrally a pair of ornaments, directed sub- 

 dorsally and subventrally respectively, being flaplike and bont back- 

 ward in some species, and conelike in other species. Lateral papillae 

 or amphids well developed, prominent. Buccal capsule lacking." 



For the purpose of separating Epomidlostamum crami from the 

 other species of the genus the following key is appended. In this key 



