530 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.55. 



confusion in regard to the position which one of the genera should 

 occupy, to attempt to determine the relation which the group bears to 

 the other groups in the Ichneumonidae. It is hoped that this has 

 been accomplished. 



The genus Helcostizus (Foerster) Dalla Torre {=■ Brachycentrtis 

 Taschenberg) has been variously assigned to the Cryptinae and the 

 Tchneumoninae (Pimplinae), to the former because of its pentagonal 

 areolet, carinate propodeum, jjetiolate first tergite, and very faintly 

 impressed sternauli, and to the latter because of its evident affinities 

 with Echthrus Gravenhorst and its strongly Pimpline habitus. Cryp- 

 toideus Ashmead was referred by its author to the Cryptinae, where 

 Viereck also placed his synonymous Xylophruridea. All of the 

 authors who have placed these genera in the Cryptinae have, how- 

 ever, been content to leave Echthrus in the Pimplinae in spite of the 

 fact that it has all of the Cryptine characters mentioned even more 

 strongly developed than has either of the other genera. Rohwer'- 

 reverses the arrangement, placing Flelcostizus in the Pimplinae and 

 Echthrus^ at least as represented by the American species, in the 

 Cryptinae on the lack of the sternauli in the former and their pres- 

 ence in the latter, making this the final cliaracter for separating the 

 two subfamilies. It seems evident, however, that the very peculiar 

 inflated front femora, truncate apical joint of the antenna, and me- 

 dially dentate clypeus should be taken as evidence of their relation 

 to each other rather than that they should be separated by a character 

 that shows such variation as does the strength of the sternauli even 

 in the true Cryptinae. 



To the present writer it seems that these three genera and prob- 

 ably Xylophrurus (Foerster) Schmiedeknecht ^ form a connecting 

 link between the Ichneumoninae and the Cryptinae not exactly refer- 

 able to any at present recognized tribe in either subfamily, but Cryp- 

 tine rather than Ichneumonine. Through Cryptoideus the group is 

 much more closely related to Cryptus than to any genus in the Ich- 

 neumoninae. In the typical Cryptus the general form and structure 

 is very similar to that of Cryptoideus^ the clypeus is of similar struc- 

 ture though lacking the median tooth, the venation is the same, the 

 propodeal carination is similar, the first tergite is similar, and the 

 front tibiae are swollen, though not distinctly inflated nor distinctly 

 constricted at the base. 



All of the species discussed will run more or less satisfactorily in 

 Ashmead's key to the Cryptini to either Xylophrurus or Cryptoideus. 



The recent discovery in the United States National Museum of an 

 undescribed species representing an apparentlj^ new genus belonging 



» Proc. Ent. Soc. Wash., vol. 15, 1913, p. 185. 



* The writer Is not familiar with Xylophrurtia, but from description It seems to be 

 rather closely allied to Cryptoideus Ashmead. 



