presso-carinate ; middle coxae narrowly separated ; metasternal wings rather nar- 

 row externally, their width between the mesocoxae and coxal plates about one- 

 third, the length of the latter. Hind tibiae with a row of punctures along the 

 inner margin. Pro- and mesotarsi very broadly dilated, the fourth joint barely 

 half as wide as the third; protarsal claws of male elongate, nearly straight and 

 slightly sinuate beneath ; claw joint dentate beneath. The four anterior tarsi are 

 furnished beneath with extremely large circular palettes, which appear to rest 

 directly on the derm or in part to be supported on very short pedicels. Length 

 9.2 to 10 mm. ; width 5.3 t* 5.7 mm. 



The type, in my own collection, is a male from Waghorn, Alberta, 

 from whch locality I have seen a considerable series, the greater num- 

 ber in Mr. Sherman's collection. A series of specimens (Sherman 

 collection) from West St. Modest, Labrador, appear to be identical 

 in every respect but are much smaller, being barely 8 mm. in length. 



A fine big species which bears considerable resemblance to the 

 European fuscipennis, with which it would be associated in Sharp's 

 Group 19, but it may at once be separated from that species and from 

 all others in our fauna by the last protarsal joint dentate beneath in the 

 male. 



A. coxalis Shp. On Dytiscidae, 1882, p. 535. 



Broadly oval; head and thorax flavotestaceous, the former marked with black 

 posteriorly, the latter with vague dusky median transverse divided spot, some- 

 times wanting; elytra fuscotestaceous, the margins yellowish; body beneath 

 testaceous varied with blackish ; legs and antennae flavo- or rufotestaceous. 

 Elytra minutely regularly reticulate, dorsal series of punctures sub-obsolete. 

 Prosternal process angulately convex; metasternal length between middle coxae 

 and coxal plates much less than half the length of the latter. Pro- and meso- 

 tarsi of male broadly dilated and with large palettes beneath; anterior protarsal 

 claw very short and rather stout, posterior claw slender, rather more than twice 

 as long, and a little sinuate beneath. Length 8.2 to 8.3 mm. 



Two specimens are before me, collected and donated by W. S. 

 McAlpine, who took them at Homer, Alaska, August 7, 1911. 



Sharp described this species from Eastern Siberia (Angara) and 

 Lapland. It has not before been recorded from North America. 

 Co.valis bears a general resemblance to aja.\~, especially the smaller 

 Labrador form, but is easily separable by the male tarsal characters. 



A. anthracinus Mann. Bull. Mosc. 1852, II, p. 304. 

 ? scapularis Mann. 1. c. p. 303. 



Moderately elongate oval ; black, head and thorax aenescent, elytra scarcely so ; 

 marginal bead of thorax and sides of elytra at the humeri more or less vaguely 

 rufescent. Surface only moderately shining, the reticulation coarse, deep, and 

 irregular, the meshes as large on the elytra as on the thorax. Antennae rufous ; 

 legs dark rufous, the femora usually darker. Male tarsi strongly incrassate and 

 bearing beneath large circular palettes; protarsal claws of male somewhat 

 elongate, little curved except at tip, the anterior a little less slender and scarcely 

 sinuate beneath, the posterior lightly sinuate. Length 6.8 to 8 mm. 



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