NO. 1487. NORTH AMERICAN DI(;GER WASPS—FERNALI). 349 



though the literature of this species and of C. tliomse, is so mixed that 

 references to the latter may in some cases belong here. 



The tirst few dorsal abdominal plates are frequently noticeably sil- 

 very pubescent, and this has in some cases been supposed to be a 

 specific distinction, but as this is also quite pronounced in some speci- 

 mens of C. tJiOinm it can not be relied upon for this purpose. 



A good figure of one of the less pubescent individuals of C. hifoveo- 

 hdidib is given as fig. 23, Plate XI, of the Insect Book. 



Subgenus ISODONTIA Patton (genus). 



Isodontia Patton, Proe. Bos. Soc. Nat. Hist., XX, 1880, p. 380. 

 Isodontia Kohl, Ann. natur. Hofmus. Wien, V, 1890, p. 114. 

 Isodoniia Kohl, Ann. natur. Hofmus. Wien, XI, 1896, p. 319. 



Type: Chlorlon {hodontia) harrin. (Designated b}^ Patton.) 

 Claws with two l)lunt teeth near the base of their inner ])order. 

 Median segment without a stigmatal groove, rarely with a faint trace 

 of one near the hinder end. Stigma of the first dorsal abdominal plate 

 in front of the middle. Tarsal comb of the female absent. Comb teeth 

 of tiie hind tibial spine not tooth-like but forming a row of closely set 

 hairs. Inner borders of the eyes parallel or converging downward, 

 the latter especially in the males. Second cubital cell of the fore wing 

 rhombic, rhomboidal or approaching a rectangular form, at least as 

 broad on the cu))ital vein as it is high. Distance between the second 

 and third transverse cubital veins on the radial cell greater than that 

 between the second transverse cubital and second recurrent veins on 

 the cubital vein. Collar not strongly developed, not as high as the 

 mesonotum. Mesonotum punctured. Dorsum of median segment 

 dull, without markings, or slightly punctured, rarely with transverse 

 striations. Petiole long, generally bent upward. Mandible with two 

 or three teeth; not reaching the base of the other when closed. Abdo- 

 men rather flattened dorso-ventrally; in the male with rows of rather 

 coarse, backwardly pointing hairs beneath. Body as a whole usually 

 slender. (Plate IX, fig. 17; Plate X, fig. 20.) 



This subgenus is easily separated from those already considered by 

 the strikingly difi'erent form of the second cubital cell, in which it 

 comes nearest to ProteroHphex, and hy the length of the petiole. From 

 JWderosphex it is distinguished ])y the absence of a stigmatal groove 

 (except in one case) as well as by other and less noticeable characters. 

 In both it and Frotero.yf/ic.r the eyes seem to be carried inward toward 

 the center of the head so that they are nearer each other there than a 

 short distance below, though they may converge toward the clypeus 

 till nearer each other than at the top. 

 Proc. N. M. vol. xxxi— 06 23 



