On Aquatic Carnivorous Coleoptera or Dytiscide. 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 strize on the basal portion of the 
elytra are much deeper and coarser than in the male, so that they appear more 
approximate. 
Northern Europe, Siberia, (Sweden, Lapland, Finland to 69° Sahlberg). 918. 
972. Dytiscus striatus, Lin., Cymatopterus striatus, M.C.—Ovalis, elongatus, 
haud angustus, sat convexus, subtus niger, supra capite anterius rufo, posterius 
nigro, rufo-bimaculato, thorace testaceo, medio plaga nigro-fusca, elytris fuscis, 
lateribus testaceis, antennis pedibusaue rufis; prothorace crebrius reticulato ; elytris 
profunde transversim strigosis, strigis approximatis. Long. 172, 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 striae 
on the elytra of the male are moderately deep and but littie 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 Germany ; Siberia, sec. Sahlberg). 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 femoribus infuscatis, pedibus postertoribus 
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. 87 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. paykulh, and the re- 
semblance is increased when, as is occasionally seen, such individuals have the 
epipleure 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, Syria, (Sweden ; Finland 63°, Sahlberg ; Britain, Orkney Islands ; France, Germany 
Spain, Italy, Corsica, Crete, Smyrna). 920. 
: 4M2 
