38 PROC. ENT. SOC. WASH., VOL. 54, NO. 1, FEBRUARY, 1952 punctures l)econit> oV)solete outwardly as minute punctation becomes more noticeable; costae barely tracea>)le through shallow, outer striae of each elytron. Scutellum smooth. Pygidium transversely, strongly convex over basal third, strongly concave over remainder ; basal third closely, finely punctate, less closely over middle third, and apically with increasingly very close, minute punctures; basal third with moderately close, semi-erect yellowish hair, apical two-thirds with a very few, scattered, erect hairs. Pubescence of underside yellowish and not so closely decumbent. Paratypes. — Paratypes differ in that one male specimen is heavier and more fully developed than holotype, frontal horn being about as long as length of head, bifurcation about one-third its total length; pronotum at anterior third bearing a sharp, median, anteriorly directed horn or tubercle, behind this, at basal third, a small, smooth, impunctate area, and lateral margin having a slight, depressed emargination before mid-dle. Length of this specimen 33 mm., width 19 mm. Female paratypes vary from 27 to 31 mm. long and 16 to 17 mm. wide. Holotype, U. S. National Museum No. 61078. Santa Rita Rano'e Reserve, Pima Co., Arizona, 4000 ft., mesquite-desert grassland, 13 Aug. 1949, at light, F. Werner & W. Nutting Allotype female, 2 mi. SW of Patagonia, Santa Cruz ('o., Ari-zona, rich willow-cottonwood bottom, 4050 ft., 30 July 1948. at light, F. Werner & W. Nutting. Paratypes: ARIZONA: one female same data as holotype ; one female, Phoenix. Lie-beck Collection, in Museum of Comparative Zoology at Har-vard; one male, Tucson, H. H. Brown, in USNM; one male and one female, Baboquivari Mts., 23 July 1949, F. H. Parker, in Parker Collection. Megasoma puncinlatus is quite near M. thersites Lee, but averages smaller in size, lacks the upper surface pubescence of that species, the median pronotal tubercle is not bifurcate in the specimens at hand as in thersites, and the median pronotal tubercle of the female is not binodose. THE CALIFORNIA SPECIES OF MITE-BEARING STENODYNERUS (Hymenoptera, Vespidae) By Eichard M. Bohart, University of California, Davi^ The subgenus Parancistrocerus was established by J. C. Be-quaert in 1925 (Trans. Amer. Bnt. Soc. 51 : 64) for the Ameri-can and African species of solitary vespids with a mite cham-ber under the hind margin of the first abdominal tergite. The originally designated type was the well known eastern species, Odynerus fulvipes Saussure. With the nine described below, thirty-five species and subspecies are now known from the United States, and some of these are among the commonest small wasps.