402 On new Hymenoptera from the Mesilla FaJIey. 



fuscous. Abdomen witli only the faintest indication of a 

 median ridge on second segment ; covered bases of segments 

 black. Margin of third segment strongly bidentate, the 

 notch between the teeth broad and deep, the teeth large, the 

 margin beyond them gently curved, nearly straight, nob 

 angled, narrowly white. Pits about sixteen in number. 



Hab. Las Cruces, New Mexico, on Bigelovia Wrightii, 

 Sept. 23, 1895. 



Structurally this is almost exactly like C. mcsiUce, but it 

 shows none of the crimson colour of that insect, and the para- 

 psidal grooves of mesillce are almost straight. It resembles 

 also C. perpiilchra^ Cr., but that has the basin of face cross- 

 striated, and C. quadrituherculata^ Cam., but that has 

 tubercles on the vertex. 



Pemphredonidae. 

 Ammoplanus salicisj sp. n. 



$ . — Length about 4^ millim. 



Shining black, naked, with brilliant silvery pubescence on 

 face and checks and very sparse short pubescence on pleura 

 and abdomen. Head large, quadrate, broader than long. 

 Eyes converging below, front rather sparsely punctured, 

 median groove very distinct, scape yellow in front, funicle 

 yellow at extreme apex, flagellum piceous black. Anterior 

 median edge of clypeus broadly truncate, the truncation with 

 a notch on each side. ]\Iandibles black at extreme base, 

 rufous at tips, otherwise white, M'itli a conspicuous denticle on 

 the inner side, perhaps a little nearer to the base than the 

 apex. Mesothorax rather sparsely punctured, scutellum 

 obscurely punctured, tubercles with a yellow spot, basal 

 middle of metathorax smooth. Knees, anterior and middle 

 tibiai except a black stripe behind, basal two fifths of hind 

 tibige, and basal joints of tarsi cream-colour or very pale 

 yellow. Ends of tarsi rufcscent. Tegulaj dark testaceous. 

 Wings hyaline, nervures and stigma black. Marginal cell 

 about or nearly as long as first (and only) submarginal, but 

 not so broad, its apex broadly truncate. Recurrent nervure 

 joining marginal cell at its middle. Abdomen rather small, 

 punctures minute and scattered, first segment smooth. Py- 

 gidium with strong sparse punctures. 



Hab. Las Cruces, New j\Icxico, on Salix, May 2, 1896. 



The silvery hairs of the face are broad and flattened, 

 representing the first advance towards jilumosity. A smaller 

 species oi' A nwioj)la7ius is found at Santa Fe. 



