On Aquatic Carnivorous Coleoptera or DytiscidcB. 319 



serrulatis, pone medium subsinuatis, angulis posterioribus subrectis, medio longi- 

 tudiualiter caualiculato ; elytris punctato-rugulosis, sat distincte striatis ; prosterni 

 processu sat elongato. Long. 121, lat. 6 m.m. 



I have seen only a single individual of this species, which is closely allied to A. 

 insolens, but has the hind angles of the thorax less acute ; the elytra are more 

 elongate and less convex, and the prosternal process is more elongate and parallel 

 sided. The lesfs are longer than in A. insolens, and thouo^h the tarsi are broken 

 off from the individual, except the two basal joints of the posterior ones, these are 

 much lonsrer than in A. insolens. 



^&^ 



North America; (Viincouver's Land.) 233. 



178. Amphizoa lecontei, Matthews, Cist. Ent. 1. p. 121. — Rufo-nigravel picea, sine 

 pubescentia ; opaca, obsolete rugulosa ; thorace elytris multo angustiore, lateribus 

 obsolete serratis, pone medium baud sinuatis, angulis posterioribus subobtusis, 

 basi recte truucato, medio longitudinaliter canaliculato ; elytris ampliatis, minus 

 fortiter rugulosis, minus distincte striatis, longitudinaliter subcostatis, epipleuris 

 latis; prosterni processu anterius elongato. Long. 12f lat 7\ m.m. 



This species is readily distinguished by the broad elytra, which are longitudinally 

 subcostate, and have their inflexed part much broader, and by the fact that the 

 edges of the prosternal process are continued forwards beyond the front coxse 

 towards the front edge of the thorax, which however they do not nearly reach. 



North America ; (Vancouver's Land.) 234. 



III. 2.— Tribe HYDR< )P( )i:iDES. 



Prosternum deflected between the frcjnt coxae, so that the prosternal process has 

 a diil'crent plane of direction from that of the prosternum. Front tarsi usually four- 

 jointed (five-jointed in Sternopriscus, Necterosoma and Celina). Scutellum usually 

 quite concealed (but exposed in Celina). 



This is the most extensive tribe of the Dytiscidae. 



Posterior coxal 

 ca^'ities widely 

 separated; each 

 with elongate \ — — — — Hydrovatini. 



coxal excision 

 and extra rimal 

 lobe. 



{Vide p. 320.) 



