388 COLEOPTEKA OF NORTH AMERICA. 



Head prominent, not constricted behind, received into 

 the thorax not as far as the eyes, which are small, convex, 

 rounded, and coarsely granulated; clypeus short, distinct; 

 labrum prominent; mandibles short, tip slightly prolonged, 

 acute, inner edge with two small, distant teeth. 



Antennge as long as the head and thorax, 11-jointed, last 

 three joints one-half larger than the preceding ones, inserted 

 under very small oblique frontal ridges. 



Erothorax subcylindrical, lateral suture obliterated; coxal 

 cavities entirely. closed behind, and widely separated. 



Mesosternum moderately long; coxal cavities surrounded 

 by the sterna, side pieces concealed by the Imraeri of the 

 elytra. 



Metasternum very short, side pieces not very wide. 



Elytra separate, broadly rounded at tip, covering the 

 abdomen; epipleurte extremely narrow, wings wanting. 



Abdomen with six ventral segments; the first and second 

 connate, the fifth truncate at tip, and closely united with 

 the sixth. 



Legs long; anterior coxse globose, prominent, widely 

 separated, without trochantin ; middle ones very widely 

 separated, rounded, without trochantin ; hind ones very 

 widely separated, oval ; tibiae slender, with very small spurs; 

 anterior and middle tarsi 5- jointed,, hind ones 4-jointed; all 

 the joints short and equal, pubescent beneath, except the 

 last, which is very long and stout, with large, simple claws. 



The characters above detailed are abundantly sufficient to 

 separate as a distinct family the sinj^^le species, Aegiaities debilis 

 Mann., from Alaska, upon which it is founded. 



The insect is oY small size, and of I)lack color, with the elytra 

 jiTadualiy widened from the thorax, and impressed with punctured 

 striae, gradually becoming eifaced towards the sides. 



Regarding the affinities of this genus various opinions have 

 been entei-tained. Mannerheim hesitated between Scydmsenidae 

 and Tenebrionidas; Motschulsky, on account of the form of the 

 tarsi, placed it among the Parnida^ ; Gerstaecker placed it in 

 Tenebrionidae near Helops. It is of such extreme rarity as to 

 have been seen by but few entomologists. 



