On Aquatic Carnivorous Coleoptera or DytiscidcB. 711 



anterioribus rufis, tarsis intermediis piceis, pedibus posterioribus nigricantibus ; 

 elytrorum epipleuris versus apicem paruin latioribus. Long. 30, lat. 18 man. 



In the male the front tarsi are small, attaining about 2^ m.m. in the transverse 

 direction, their claws are rather short ; the middle feet have elongate sexual 

 pubescence on the three basal joints, their claws are of moderate size and simply 

 curved, the inner one being a good deal shorter than the outer. The female I have 

 not seen. 



The species much resembles Cybister costalis (No. 1116), but is smaller and 

 narrower, and the male anterior tarsi are smaller, and the claws of the intermediate 

 feet much less developed, and the epipleurae of the elytra are much narrower. It 

 is smaller than C. robustus, and has the epipleura; narrower, 



Panama. 1108. 



1113. Cybister robustus, Aubd, Trocjus robustus, M.C. — Ovalis, latus, anterius 

 angustatns, sat convexus, nigi'icans, capite anterius prothoraceque ad latera tes- 

 taceis, elytris vitta intramarginali, ad apicem lata sed parum determinata, testacea ; 

 pedibus quatuor anterioribus rufis, tarsis intermediis piceis ; pedibus posterioribus 

 piceis, tibiis superne rufescentibus, temoribus nigris ; elytrorum epiplemus sat latis. 

 Lonsr. 3.5, lat. 20 m.m. 



I have seen only one male of this species ; the sexual characters of that sex 

 seem to be the same as in M. obesus, the front tarsi being scarcely 2^ m.m. in the 

 transverse direction. 



South America. (Buenos Ayres, fide Castlenau). 1109. 



1114. Megadytes perplexus, n. sp. — Ovalis, latus, anterius angustatns, convexus, 

 supra olivaceo-niger, capite anterius prothoraceque ad latera testaceis, elytris vitta 

 intramarginali ad apicem obsoletescente testacea ; subtus niger, pedibus quatuor 

 anterioribus rufis, tarsis intermediis piceis ; pedibus posterioribus piceis, tibiis 

 superne rufescentibus, femoribus nigris ; elytris ad apicem punctis impressis con- 

 spicuis, epipleuris parum latis. Long. 35, lat. 20 m.m. 



The characters of the male are the same as in Cybister robustus ; the species 

 must indeed be very closely allied to C. robustus, but the only individual before 

 me I cannot reconcile therewith ; it differs somewhat in colour and form, and has 

 the epipleurfe decidedly narrower throughout its whole length. It is perhaps still 

 closer to M. obesus, but is considerably larger : in both these species the impressed 

 punctures on the apex of the elytra are much more conspicuous than in the allied 

 species. 



The only individual I have seen of this species existed in Edwin Brown's 

 -collection, without any indication of locality. 



South America ? 1110. 



