A EEMAKKABLE NEW GENUS AND SPECIES OF MER- 

 MITHID WORMS FROM JAMAICA. 



By G. Steiner 



Of the Bureau of Plant Imlustnj, United States Department of Agriculture. 



On September 29, 1922, the Federal Horticultural Board, through 

 the kindness of E. R. Sasscer, submitted five ]Mermithid specimens 

 taken at Philadelphia, Pa., from soil about plant cuttings from 

 Jamaica hj Inspector C. A. Davis on September 25, 1922. These 

 rive Mermithids all belong to the same species, which is new to 

 science, and is the representative of a new genus, remarkable in 

 several respects. Our knowledge of the Mermithidae is still very 

 limited. This family of parasitic nemas is of high economic im- 

 portance and much more interest should be taken in it. 



ALLOMERMIS,! new genus. 



Diagnosis. — A genus of the family of Mermithidae with only four 

 head fafillae., with a mouth opening lying ventrad behind the head 

 papillae, toith amphids {lateral organs) near the front of the head- 

 end and so lying farther forward than the head papillae, with a 

 single dorsal suspensory or retractory muscle on the oral part of the 

 oesophageal tuhe, with a vagina l)ent in a tr'ansverse 2)lane of the 

 body, tenth a pair of spicula and the cuticle loith cross-fibers. 



Type species. — AUom-ermis trichotopson^ new species. 



The genus is closely related to Paramermis, but differs from it in 

 having only four head papillae, whereas Parainermis has six; it 

 differs also in having in the male two spicula while Paramermis has 

 only one. The presence of cross-fibers in the cuticle is also a distinc- 

 tive character since no Paramermis hitherto described has them. 

 The genus Pseudomermis., which has the same number of head 

 papillae as Allomermis (only four), differs in the position of the 

 amphids. In Pseudomermis they have the normal position liehind 

 the lateral papillae and the mouth opening has its normal place on 

 the front of the head-end. 



Therefore the new genus Allomermis seems to be well separated 

 and distinctly different from any other hitherto described Mermithid 

 genus. As to relationship, it stands next to Pseudomermis. Consid- 

 ering the fact that Allomermis has the mouth opening and the 



1 aWot = otherwise, differently. 

 - TpixuiTOi = hairy, i^ou =egg. 



No. 2527 — Proceedings U. S. National Museum. Vol. 65. Art. 14. 

 45554— 25— ri-oc.N.M.vc)1.65 27 1 



