TRICHOPTERYOIDAE. 19 



seventh or even the eighth internal ones to be seen; the last 

 three or four dorsal segments are entirely corneous. 



Anterior coxa) large, cylindrical, prominent, contiguous; 

 middle coxae small, rounded, widely separated; posterior 

 coxaa oval, usually widely separated. 



Legs slender; tarsi 5-joiuted, long, filiform; claws slender, 

 simple. 



This family contains small oval or rounded oval, convex, very 

 shining insects, living in fungi. The sides of the thorax are 

 oblique, and the head small, so as to make the body somewhat 

 pointed in front ; the thorax is very closely applied to the trunk, 

 and the elytra are broadly truncate, permitting the tip of the 

 conical abdomen to appear. All the known genera of the family, 

 except Amalocera, are represented in our Atlantic fauna, but 

 Scaphisoma alone has yet been obtained on the Pacific slope. 



I. Scutellum distinct ; antennae clavate ; 

 Posterior tibia? not spinous ; 

 First joint of posterior tarsi longest ; eyes emarginate. Scaphidiitm. 

 First joint of posterior tarsi scarcely longer than the second ; eyes en- 

 tire. Scaphium. 

 Posterior tibiae with rows of small spines ; eyes entire. Cyparium. 

 II. Scutellum covered by the base of the thorax ; antennae capillary ; 

 Posterior coxae widely distant ; 



Antennae with the joints 9 — 11 wider. B.eocera. 



Antennae with the joints 6 or 7 — 11 wider. Scaphisoma. 



• Posterior coxae not widely distant ; body narrow, compressed. 



Toxidium. 



Fam. XIII.— tkichopterygidae. 



Mentum quadrate. 



Maxillas exposed at the base, which is large, with two 

 lobes, the inner one ciliate and hooked; palpi 3-jointed, last 

 joint acicular. 



Antennae inserted at the margin of the front, 11-jointed, 

 verticillate with long hairs, the first and second joints thick, 

 3 — 7 slender, 8 — 11 thicker, forming a loosely articulated, 

 elongate club. 



Prothorax with the side pieces not distinct. 



Elytra sometimes entire, sometimes abbreviated ; wings 

 long, narrow, margined with very long hairs ; sometimes 

 wanting. 



Abdomen with seven free ventral segments. 



