Il8 CONNECTICUT GEOL. AND NAT. HIST. SURVEY. [Bull. 



peus deeply and narrowly emarginate; frontal crest un- 

 broken; third and fourth segments of antennae subequal; 

 saw-guides oblique above and below and obliquely trun- 

 cated at apex. Length 7 mm corticosus 



Head and thorax dark brown; body black, with head, anten- 

 nae, pronotum, mesonotum, and dorsum of abdomen more 

 or less, upper half of pleura, and saw-guides, dark brown; 

 clypeus broadly and shallowly emarginate; frontal crest 

 unbroken; antennae with third segment longer than fourth; 

 saw-guides short, obliquely truncate, pointed at tip. 

 Length 4.3 mm gregarius 



13. Anterior pair of legs entirely pale; vertex finely tuberculate; 



ocellar basin with lateral walls minutely but sharply raised, 

 obsolete posteriorly; frontal crest acutely elevated, angu- 

 lated, and extending nearly to inner orbits; median fovea 

 broad, extending on each side over bases of antennae; saw- 

 guides broad, straight on upper margins, obliquely truncated at 

 apex, bordering hairs minute and scattering; body shining 

 black, with apex of clypeus, mouth-parts, pronotum in great 

 part, tegulas, anterior pair of legs, posterior pair of legs except 

 bases of coxae and apices of femora and tibiae and all of tarsi, 

 venter of abdomen except at apex, lateral margin and more or 



less of apex of tergum, yellowish white. Length d-y mm 



corniger 

 Anterior pair of legs more or less marked with black 14 



14. Frontal crest strongly developed, slightly broken at center, 



and not reaching inner orbits; ocellar basin with distinct 

 sides but not strongly elevated; median fovea distinct, 

 broadening posteriorly into a suture beneath the frontal crest; 

 saw-guides rather broad, rounded, truncate at apex, 

 straight on upper margins; body black, with tip of the clyp- 

 eus, labrum, angles of pronotum, tegulae, coxae except 

 at base, trochanters, bases of femora and tips of anterior 

 femora, tibiae except tips of posterior pair, anterior tarsi, 

 and venter except laterally at base and apex, pallid. 



Length 8 mm subalbatus 



Frontal crest distinctly elevated and unbroken, extending 

 nearly to the inner orbits; ocellar basin with sides rounded, 

 not strongly raised, and indistinct; median fovea large, 

 circular, deeply excavated; saw-guides rather slender, 

 somewhat pointed at tip, dorsal margin nearly straight; 

 body black, with labrum, bases of mandibles, angles of 

 pronotum, tegulae, coxae except at base, trochanters, tibiae 

 of anterior pair of legs and their tarsi, and venter of ab- 

 domen, yellowish or pallid. Length 6 mm palliventris 



15. Head strongly dilated behind the compound eyes 16 



Head not strongly dilated behind the compound eyes 22 



