AQUATIC IXSECTS IX NEW YORK STATE 293 



pp Apex of the abdomen not obliquely 

 trimeate; antennae with four seg- 

 ments N i t i d u 1 i d a e 



00 Ninth abdominal tergite not with short 

 cuticular spines 

 p Antennae consisting of four segnjcuts 

 q Labrum distinctly present 



N i t i d u I i d a e 

 C u c u j i d a e 



qq Labrum wanting Elate ridae 



pp Antennae consisting of three segments 

 q Labrum wanting.. ..La m j) y r i d a e 

 qq Labrum distinctly present 



]\I e 1 a n d r y i d a e 

 €6 Apex of the abdomen strongly chitinized and usually produci^d 

 into one or more prominent projections 

 f Entire abdomen strongly chitinized and cylindrical, the apex 

 squarely truncate and not produced into projections 



R h i p i c e r i d a e 

 ff Entire abdomen not strongly chitinized and, if so, never 

 truncate at the apex; flattened or cylindrical, and the apex 

 alwa3's produced into one or more prominent projections 

 g Antennae consisting of four segments 



7; Abdomen strongly chitinized only around the bases of 

 tlie chitinous projections of the apex of the tergum; 

 usually somewhat flattened 

 i Last abdominal segment produced into two strongly 

 chitinized and bifurcating processes 

 / Abdomen strongly depressed. .P y r o c h r o i d ae 

 // Abdomen cylindrical or subcyliudrical, not strongly 

 depressed 

 A' Bifurcating process of the last abdominal segment 

 with lateral spines or tubercles 



T r g o s i t i d a e 

 A- A- Bifurcating process of the last abdominal segment 

 not with lateral spines or tubercles 



Colydiidae 



Mycetophagidae 



iMalachidae 



C 1 e r i d a e 



INIelandryidae 



a Last abdominal segment produced into a single 



strongly chitinized process, which is usually slightly 



angularly emarginate at apex Mordellidae 



hJi Abdomen strongly and evenly chitinized throughout, 

 cylindrical or subcyliudrical 



i Labrum Avantiug Elate ridae 



it Labrum present and separated from the clypeus by a 

 distinct suture Tenebrionidae 



