On Aquatic Ca rnivorons Coleoptera or Dytiscidce. 629 



The male has the front and middle tarsi well dilated and considerably compressed. 

 The reticulate sculpture of its thorax is very well marked ; the female has this 

 reticulate sculpture just a little deeper, while the striae on the basal portion of the 

 elytra are much deeper and coarser than in the male, so that they appear more 

 approximate. 



Northern Eurojie, Siberia, (Sweden, Lapland, Finland to 69° Salilberg). 918. 



972. Dytiscus sti'iatus, Lin., Cymatopterus striatus, M.C — Ovalis, elongatus, 

 haud angustus, sat convcxus, subtus niger, supra capite anterius rufo, posterius 

 nigro, rufo-bimaculato, thorace iestaceo, medio plaga nigro-fusca, elytris fuscis, 

 lateribus testaceis, antennis pedibusoue rufis ; prothorace crebrius reticulato ; elytris 

 profunde transversim strigosis, strigis approximatis. Long. 171, lat. 9 m.m. 



In the male the reticulation of the thorax is quite distinct and regular and covers 

 nearly all the surface, and in the female it is a little deeper ; the transverse strise 

 on the elytra of the male are moderately deep and but little distant from one 

 another ; in the female they are much deeper and coarser, but at the extremity 

 become fine and are on that part the same as in the male. The male has the front 

 and middle tarsi broadly dilated and but little compressed. 



Northern Europe, (Sweden, Finland, North Geruiauy ; Siberia, sec. Sahllierg). 919. 



973. Dytiscus fuscus, Lin., Cymatopterus fuscus, M.C. — Ovalis, sat elongatus et 

 convexus^ subtus niger, supra capite anterius rufo, posterius nigro rufo-bimaculato, 

 prothorace medio late fusco, lateribus testaceis, elytris fuscis lateribus testaceis, 

 antennis pedibusque anterioribus rufis, his femoribns infuscatis, pedibus posterioribus 

 nigricantibus, tarsis dilutioribus ; prothorace crebre subtiliter vermiculato, elytris 

 minus profunde transversim strigosis, strigis approximatis ; abdomine sutura secunda 

 ventrali utrinque prope medium rude serratulo. Long. 16, lat. 8? m.m. 



The male has the basal joints of the front and middle tarsi moderately dilated 

 and much compressed, and furnished beneath with four series of rather large, quite 

 round, closely packed palettes ; the marginal hairs are comparatively little developed. 

 There is no sexual difference of sculpture. 



The species varies somewhat in colour and a good deal in length ; the more 

 elongate and darker specimens resemble a good deal, C paykulli, and the re- 

 semblance is increased when, as is occasionally seen, such individuals have the 

 epipleurse infuscate ; but the coarse short plicate elevations of the second ventral 

 suture in D. fuscus allow it to be readily recognized even in its extreme varieties. 



Europe, Algeria, Sp-ia, (Sweden ; Finland 63", Sahlberg ; Britain, Orkney Islands ; France, Germany 

 Spain, Italy, Corsica, Crete, Smyrna). 920. 



4 M2 



