254 INSECTS. COLEOPTERA. 



* With wings. 



N. arenaria, Lat. Body eight lines long, yellowish or reddish, with 

 the elytra striated and crossed by two black bands formed of many 

 spots. Inhabits coasts of Europe Lat. Gen. pi. 7- fig. 6. 



** Without wings. 



N. Helwigii, Panz. Shining black, with the antennae, palpi, and 

 feet obscure brown ; thorax with a deep transverse line on the 

 fore part, uniting with another longitudinal one ; elytra slightly 

 dotted. Nouv. Diet. xxii. 410. 



Gen. BEMBIDIOX, Lat. Carabus, Fab. 



With the penult joint of the exterior palpi largest, swelled into 

 a pear form, and the last very short and subulate. 



H.J1avipes,Ijat. (Cicindela, Lin.) About two lines long ; thorax 

 a little narrower than the head, in the form of a truncated heart, 

 as long as broad ; eyes large ; under part of the body of a black- 

 ish green ; upper part marbled with coppery red ; two large deep 

 points near the suture on each elytrum ; base of the antennae, 

 palpi, and feet yellowish. Common in the neighbourhood of 

 Paris. Lat. Gen. i. 183. 



2. AQUATIC. 



Four posterior feet sometimes compressed, thinned towards the 

 end and ciliated, in the form of plates or fins, and proper for 

 swimming ; jaws arched or hooked immediately beyond the 

 origin of the palpi ; body generally ovoid or oval, with the 

 eyes slightly projecting, and the thorax much broader than 

 long. 



TRIBE III. HYDROCANTHARI. 



Antennae filiform, longer than the head ; with eleven joints, in- 

 serted near the labrum ; exterior palpi filiform ; eyes two ; 

 five joints in all the tarsi. 



This tribe of insects pass the greater part of their life in tranquil waters. They 

 swim well, and come to the surface at intervals to respire. The larvae have a long 

 and narrow body composed of twelve segments, of which the first is the largest ; the 

 head long, with two powerful arched mandibles ; six feet ; and on each side five or 

 six black tubercles, which have been taken for eyes. The larvae leave the water at 

 the period of their transformation, and conceal themselves in the ground. 



I. Base of the posterior feet naked, and without a plate in the form of a shield ; an- 

 tennae of eleven joints, inserted near the labrum ; exterior palpi not subulate. 



1. Five distinct joints in all the tarsi. 



A. Exterior palpi filiform ; anterior tarsi not folding under the leg. 



a. Labial palpi not forked ; middle of the antennas not tumid. 



Gen. DYTISCUS, COLYMBETES. 



b. Labial palpi forked ; antennas tumid or thickest in the middle ; spur of the an- 

 terior legs of the male in the form of a plate or lamina, covering the first joint of 

 the tarsus. 



Gen. NOTERUS. 



