96 



INTRODUCTION. 



the Clavicornia that it seems better not to separate thein widely 

 in the present state of our knowledge. With regard to the order, 

 and in many cases the constitution, of the families of this group, 

 there is great difference of opinion, and it is best, perhaps, to 

 leave any detailed discussion on these points to the specialists 

 who will be taking up these sections. In the succeeding pages 

 several other families are noticed as belonging to the Clavicornia,. 

 which do not come within the scope of Ganglbauer's work. 



Key to ilie Indian Families. 



I. Maxillary palpi elongate, often much 

 longer than the antennae ; antennae with 

 from six to nine joints, terminating- in 

 a club; tarsi five-jointed ; habits aquatic 



or subaquatic Hydrophilidae, p. 128. 



II. Maxillary palpi not abnormally elongate. 



i. Antennas subgeniculate Synteliidae, p. 99. 



ii. Antennas not geniculate. 



1. Antennas very short, scarcely as long 



as the head, abnormal. 



A. Second joint of antennas strongly 



developed, ear-shaped ; habits [p. 126. 



aquatic or subaquatic Dryopidae (Parnidae), 



B. Antennas with joints 5-11 forming 



a very short oblong club ; habits 



fossorial Heteroceridae, p. 130. 



2. Antennas more or less elongate, clavate 



or filiform. 



A . Anterior coxas with the trochanters 



of the front legs forming two 

 plates which conceal the pro- 

 sternum ; tarsi short, four-jointed; 



habits subaquatic Georyssidae, p. 126. 



B. Anterior coxas normal. 



a. Tarsi long, five-jointed ; claws 

 strongly developed for clinging 

 to stones in running water. . . . Elmidae, p. 126 *. 

 h. Tarsi and claws not strongly 

 developed for clinging. 

 a*. Anterior coxas with a free 

 trochantin. 

 at ■ Posterior coxas not grooved 

 or sulcate. 

 a%. Tarsi five-jointed, with 

 the first joint very 



short, and the fourth [p. 100. 



normal Trogositidae (Ostomidae), 



b\. Tarsi five-jointed (rarely 

 heteromerous), with the 

 first joint not short and 



the fourth very small . . Nitidulidae, p. 104. 



* We have, after some consideration, included the Elmid.e under the 

 DRYOPiDiE, but as the point is somewhat doubtful, we have left the table 

 unaltered. 



