BY G. R. WATERHOUSE, ESQ. 293 



two basal joints long, the rest forming an elongate club : palpi as 

 long as the head and thorax, three-jointed : the basal joint long, 

 bent, and clavate, second moderate, thickened at the apex : termi- 

 nal joint long, thickened in the middle, attenuated at each end. 



Sp. 1. Hyd. riparia. Atra, nitida; capite thorace angustiore, 

 inter oculos profunde pimctato ; thorace longo, lateribus 

 dilatatis, dense jJunctato, sidco lojigitiidinali ntrinqiie ad 

 marginem : elytrls piceo-brunneis, llneari-elongatis, ajnce 

 rotundatis et distincte punctato-striatis : pedibus, antennis, 

 palpisque piceo-ferrugineis out piceis. (Long. corp. 

 11— U lin.) 



Hyd. riparia. Kugellan. Schmeid. Mag. 578. 



In this and the three following species, the eyes are but 



slightly prominent, and the head is rather elongate, with the 



sides nearly parallel ; the body is also very linear. 



I have taken several specimens of this species in the river 



Wandle, Wandsworth. Hebden-bridge ; Mr. Gibson. 



Sp. 2. Hyd. pulchella. Prcecedentibus {nigrita et gracilis) 

 minor : caput triangulare antice obtiisum, nigrum, nitidum, 

 punctulatum: antennis palpisque rujis : thorax latitudine 

 paullb breviore, lateribus rotundatus, postice paullb magis 

 angustatus, basi ajnceque truncatus, sup)ra punctatus, disco 

 subtilius ; obsoleto canaliculatus , sulcoque utrinque longi- 

 tudinali versus latera impresso : color niger, nitidulus 

 margine antico posticoque dilute latiora, oblongo-ovata, 

 convexa, j)unctato-striata, picea: corpus subtus nigrum, 

 pedibus riifis.^ 



Hyd. pulchella. Miill. Germar. Ins. Spe. Vol. I. p. 94. 

 Curtis s Brit. Ent. p. 308. 

 Not having a specimen of this species, which is introduced 



in Mr. Curtis's " British Entomology," I have given Germar's 



description. 



Sp. 3. Hyd» concolor. Pallide testacea; capite inter oculos 

 punctato : thorace lato, lateribus dilatatis, dense punctato : 

 elytris elongatis, linearibus, manifeste punctato-striatis. 

 (Long Corp. 1 J lin.) 



Allied to H. riparia, but at once known by its pale colour : the 

 head is rather smaller in proportion, the thorax is broader, and 



'' Is not the word elytra omitted ? the description does not seem quite intelli- 

 gible. — Ed. 



