BASCYLLIDAE. 16t 



Cox^e, anterior oval, transverse, with a distinct trocliantin ; 

 middle ones rounded, angalated externally, separated by the 

 anterior part of the metasternum ; hind ones transverse, 

 nearly contiguous. 



Legs stout; tibiai dilated, armed with rows of spines, and 

 fitted for digging; tarsi 4-jointed, second and third joints 

 shorter than the others, not lobed beneath, but fringed with 

 long hairs; claws simple. 



This family consists of but a single genus, Heterocerus ; it is 

 represented in every portion of our territory. The species ai'e 

 numerous, but are very similar in form and color, so that care 

 is necessary in distinguishing Ihem. They are oblong or sub- 

 elongate, oval, densely clothed with short silky pubescence, very 

 finely punctuate, and of a brown color, with the elytra usually 

 variegated with undulated bands or s[)ots of a yellow color. 

 The}' live in galleries wduch they excavate iu sand or mud at the 

 margin of l)odies of water, and, when disturbed, run from their 

 galleries and take flight, after the manner of certain species of 

 Bembidiuni. 



Fam. XXXIX.— dascyllidae. 



Mentum quadrate, corneous ; ligula large, membranous, 

 frequently divided into narrow lobes; palpi 3-jointcd. 



Maxillie' exposed at base, with two lobes, variable in form, 

 but not armed with hooks, except in Eucinetus; palpi 4- 

 jcinted. 



Antenme distant, inserted immediately in front of the 

 eyes, under a slight ridge, 11-jointed, more or less serrate, 

 rarely pectinate or flabellate. 



Head sometimes prominent, but usually deflexed, with the 

 epistoma sometimes distinct from the front; mandibles not 

 prominent. 



Prothorax with the side pieces not separate; coxal cavi- 

 ties transverse, widely open behind; prosternum sometimes 

 extending behind the coxte, but usually not. 



Mesosternum small, sometimes excavated, sometimes ob- 

 lique and flat, frequently very narrow; coxal cavities trans- 

 verse, excavated behind; epimera large, attaining the coxa;. 



Metasternum moderate, side pieces tolerably wide; epi- 

 mera usually visible. 



Elytra covering the abdomen; cpipleuraa extending to the 

 apex. 



