l08 E. T. CRESSOif. 



tarsi long and slender, dull testaceous; abdomen convex, shining, bluish-green, 

 golden in certain lights, feebly punctured, thinly clothed with a pale ochra- 

 ceous pubescence, long on basal segment and on sides of apical segments ; 

 sixth segment slightly produced and recurved at apex which is rounded ; 

 apical segment acutely bidentate ; apical margin of second ventral segment 

 broadly rounded. Length .20 inch. 



Hah. — California, (H. Edwards). This is our smallest species. 



Heriades ? denticulatum. — %. — Black, shining, closely punctured; 

 head large, subquadrate, clothed with pale pubescence, which is long, dense 

 and white on face, clypeus and cheeks beneath; antennae brown beneath; 

 thorax and scutellum thickly clothed above with short dull ochraceous pubes- 

 cence, laterally and beneath it is longer and white; basal middle of metathorax 

 smooth and polished; tegulse piceous; wings hyaline, marginal 

 cell long and pointed at tip, second submarginal cell larger than 

 the first, receiving the first recurrent nervure about one-third 

 from base, and the second near the tip; legs robust, clothed with white pubes- 

 cence, tarsi slender, rufo- testaceous at tips; abdomen as wide as thorax and 

 about as long as head and thorax combined, convex, finely punctured, depressed 

 at base and apex, apical margin of the segments with a narrow fringe of dense 

 white pubescence, wider on the sides; apical margin of sixth segment with four 

 equidistant teeth (as in figure), the lateral ones acute, the middle ones broad 

 and subtruncate at tip; venter with two bands of long dense pale pubescence. 

 Length .30 inch. 



Hnh. — Colorado, (Morrison). This may be the same as that which 

 Say describes as the % of his Osmia bucconis, the 9 of which is 

 probably that of Ahidamea jyroducta Cress. ; the clypeus, however, is 

 more or less emarginate at tip, not " entire," and the four anterior 

 tibicB have each an acute spine at tip before. 



Clielostoina calirornicum. — %. — Black, shining, very finely punc- 

 tured, head and thorax thickly clothed with a long fulvo-ochraceous pubes- 

 cence, sparse on vertex and mesothorax, and pale on cheeks and thorax be- 

 neath ; tegulse piceous; wings fuscous, second submarginal cell narrowed at 

 least two-thirds towards the marginal; legs slender, clothed with short pale 

 pubescence; abdomen narrow, convex, much incurved at tip, clothed with a 

 very short ochraceous pile, the apical margin of the segments narrowly fringed 

 with ochraceous pubescence; apical segment with three obtuse teeth, disk 

 deeply excavated; secon(J|ventral segment with a large transverse, obtuse 

 elevation. Length .35 inch. 



Hab. — California, (H. Edwards). One specimen. 



Alcidainca truncata. — %. — Black, shining, closely and rather strongly 

 punctured, head and thorax thickly clothed with long ochraceous pubescence, 

 paler on thorax beneath, and sparse on vertex and 

 mesothorax; antennae formed as in ^'J'oc^wcto, entirely 

 black; disk of mesothorax and scutellum sparsely 

 punctured; tegulse piceous; wings dusky on apical 

 margin and in marginal cell; legs clothed with pale 

 glittering pubescence, tips of four anterior tibiae with a short acute tooth before, 



