NO. 1487. NORTH AMERICAN DIGGER WASPS— FERN ALT). ■ 851 



Ahdonien. — Base of the first dorsal plate j^ellowish, the remainder 

 of the dorsal surface black, except that in some cases the hinder mar- 

 gins of the plates are pale; surface faintly pale sericeous and with a 

 few scattering- hairs on the posterior plates; beneath, minutelx^ punc- 

 tured, pale sericeous; terminal plate conical, with a rounded hinder 

 margin. 



ir///vv. — Deep fuliginous, with a slight violet retlection; discoidal 

 vein of the hind wing interstitial with the median and transverse 

 median veins; tegulfe smooth, pale jellow. 



Zfc/.s. — Coxa^, trochanters, and proximal part of the femora black, 

 haiiy, the remainder ferruginous; the black portions sometimes j-el- 

 lowish sericeous, almost pubescent; spines dark ferruginous; tips of 

 the claws nearly black; posterior tibite strongly 3'ello\v sericeous 

 behind. 



JIalc. — Dili'ers from the female in no important features not true as 

 sexual distinctions throughout this subgenus. The more tiattened 

 abdomen and the rows of backward!}^ pointing hairs on the posterior 

 margins of the ventral abdominal plates, besides the presence of thir- 

 teen segments in the antennae instead of twelve as in the females are 

 ready characters for determining the sex. 



Lemjth. — Females, 16-20 nmi.; males, 16-19 nun. 



I have seen specimens of this beautiful and apparently rare species 

 from Indian River and Biscayne Bay, Florida; from North Carolina 

 and Georgia; and from Willis, Texas, captured there June 11. 



At the time the original description was pul)lished there was no 

 species of the subgenus known in the United States which closely 

 resembled it. Larger collections, however, have revealed the fact 

 that that most variable species, Cldorloit {Isodontla) eostl])enni>< Spin- 

 ola has been taken in Mexico, and that it is sometimes difficult to sep- 

 arate the two b}" an}" one character though taken all in all the two 

 look quite ditferent. As C. costipennis is an exceedingl}^ variable 

 form it is possible that C. exornatuiii. may at some time prove to be but 

 a su})species, though 1 am at present far from believing that such is 

 the case. 



When specimens of C. exmmatuiit. were first studied in the course of 

 this work some of those in the collection of the American Entomo- 

 logical Society were found to bear the label '''' exornata^'' a manuscript 

 name, probal)ly given by W. J. Fox. As it seemed not iniprob- 

 able that this name might have been sent out on specimens it appeared 

 best to retain it for this insect to avoid any confusion which might 

 otherwise arise. 



CHLORION (ISODONTIA) COSTIPENNIS (Spinola). 



Siihex coMipetuiw Spinola, Mem. Acad. Torino, XllI, 1851, p. 54. 

 Sphe.c chrysobctpta Smith, Cat. Hym. Brit. Mus., IV, 1856, p. 257. 

 Sphex petiolula Smith, Cat. Hym. Brit. Mus., IV, 1856, p. 259. 



