158 THE ENTOMOLOGIST. 



from that in being smaller (length 10 millim.), no black hair on 

 vertex, flagellum wholly black, dark hair of mesothorax and 

 scutellum dark brown instead of black, stigma less developed 

 and piceous, bases of third and fourth abdominal segments with 

 scanty hair which is entirely black, apical bands of pubescence 

 on second to fourth segments white and well-defined. The hair 

 of the last two abdominal segments is black, except at the 

 extreme sides, and the brush of the hind tarsi is orange- 

 fulvous. 



This female is referred to crenulaticorriis instead of to 

 ruidosensis, on account of its small size, and also because the 

 venation is as in the former species, whereas ruidosensis has a 

 much larger second submarginal cell. 



Alcidamea simplex (Cresson). — This is the Heriades simplex, 

 Cress., and the Alcidamea producta, Cress., the former specific 

 name having priority. 



Megachile relativa, Cresson, 1878. — One female. Forks of 

 Buidoso Creek, N. M., July 30th, 1898, (C. M. Barber.) New 

 to New Mexico. 



Megachile ivootoni subsp. calogaster (Ckll.). — When describing 

 M. calogaster I omitted to notice the close resemblance between 

 its male and that of M. ivootoni ; they may be separated thus : — 



Spurs of hind tibia? ferruginous; vertex more closely 



punctured . . . . . ' . . . ivootoni. 



Spurs of hind tibiae piceous ; vertex less closely punc- 

 tured ......... calogaster. 



The two are doubtless geographical races of one well-marked 



species. 



Megachile sidalcece, Ckll. — A female was taken by Mr. C. M. 

 Barber in Mesilla, N. M., July 4th, 1898. It resembles the male 

 except in the usual sexual characters. The face has short white 

 hair instead of a dense pale yellow brush ; the ventral scopa is 

 white, with a few black hairs at the extreme tip. 



Megachile casadce, Ckll. — Mr. C. M. Barber took a female in 

 Mesilla, N. M., July 4th, 1898. It resembles the male except in 

 the usual sexual characters. The ventral scopa is white, even 

 to the tip. 



•/Megachile fidelis, Cr., var. n. concinnula. 



$. Length about 9^ millim., black, with thin dull white pube- 

 scence. Head large, a little broader than thorax, eyes mottled, facial 

 quadrangle a little longer than broad, narrowing below ; face, in- 

 cluding clypeus, densely covered with yellowish-white hair ; vertex 

 dull, strongly punctured, with erect hairs, some of which in certain 

 lights seem black, but this is deceptive ; cheeks with thin white 

 pubescence, a dense tuft behind near base, but the area above the 



