the terminal joint, terminal joint o^ aboul eiglii bq^" 

 ments, and not longer than the preceding joints con- 

 junctly ; eyes convex, touching the anterior edge of 

 the head; thorax v^iili seven segments, and lateral 

 scales ; feet fourteen, two anterior pairs in each sex 

 simple, Uliforni, equal^ third and fourth pairs ecpial, di- 

 dactyle, hands compressed, not dilated, finger rounded, 

 thumb oval, lanmlliforni, remaining feet gradually 

 larger, compressed, armed Avith short spines, and des- 

 titute of a nail ; hind pair largest, aniipenuitimate 

 joint lengthened eabove, and nearly attaining the tip of 

 ^he follf)\ving joint which is crenatc and spinous on 

 t!«e edge^ terminal joint compressed, serrated, and 

 spinous on the edges, and truncate at tip; anterior 

 pairs of feet furnished at their inner bases with ob- 

 loiig CA al moveable lamella^ 



Abdomen of three segments, abruptly narrower than 

 the thorax, each famished beneath with natatory feet, 

 consisting of short, rounded peduncles, supporting 

 double setse, of which tlie outer ones are longest, third 

 segment abruptly in^^ected at tip 5 tail inflected, armed 

 v.ith biiid styles, 



SPECIES. 



L. ^dytiscus. Eyes orbicular ; bodij when recent 

 white, with an abbreAiated internal fen^uginous yitta, 

 including tlie alimentary canal ; accessory seta of the 

 intermediate antennte, attaining the tip of the fourth 

 segment of tjie terminal joint j anterior pairs of feejfc 

 Jtairy. 



