On Aquatic Carnivorous Coleoptera or Dytiscide. 265 
convexus, castaneus, nitidus, leevis, sed elytris punctis magnis, imbricatis, numerosis, 
basin versus evanescentibus; sutura levi. Long. 33, lat. 2 m.m. 
I have seen only females, they are perfectly similar to Synchortus duplicatus 
except in the tarsi, and in the sculpture of the elytra, and I have little doubt the 
two are the sexes of one species. 
Madagascar. 520. 
19. Hydrocanthus rugoso-punctatus, Wehncke, Berl. Zeit. 1876, p. 221.—Ovalis, 
sat convexus, castaneus, nitidus, elytris punctis magnis, imbricatis numerosis, basin 
versus haud subtilioribus ; sutura levi. Long. 3{ m.m. lat. 2 mm. 
I have seen a single specimen, it is a female, and distinguished from Hydrocanthus 
asperatus (No. 18), by the fact that the punctures on the basal portion of the elytra 
are as coarse as those on the apical portion. 
Madagascar, (Wehncke). 609. 
I. 6.—Genus NOTERUS. 
Anterior tibia with indefinite outer apical angle, and with rather long curved 
spur ; antennze more or less incrassate ; hind tibize rather slender, scarcely flattened. 
The six species are found in the European region and Japan. 
20. Dytiscus clavicornis, de Geer. Noterus clavicornis, M.C.—Ovalis, sat 
convexus, fere angustus, sat nitidus, testaceo-castaneus, elytris punctis magnis, 
anterius subseriatis, ante basin desinentibus. Long 4, lat. 25 m.m. 
Mas, antennis incrassatis, irregularibus, articulis quinto et sexto preesertim majori- 
bus, illo quam hoc (quo valde transverso) duplo longiore ; capite subtus prosternoque 
utrinque nigro-maculatis, hoc medio deplanato. 
Fem., antennis fere regularibus, corpore subtus concolore ; prosterno medio trans- 
versim convexo. 
This species varies but little; the elytra and ventral segments are sometimes of 
more obscure colour. 
Europe. From Scandinavia to Portugal. Not common. 521. 
21. Dytiscus capricornis, Herbst. Noterus semipunctatus, M.C.—Ovalis, convexus 
sat nitidus, castaneus, antice dilutior ; elytris punctis magnis, profundis, basin versus 
desinentibus ; prosterno medio carinato. _ Long. 4%, lat. 23 m.m. 
Mas, antennis incrassatis, irregularibus, articulis 5° et 6° longitudine subzequalibus 
haud transversis ; capite subtus prosternoque latius nigricantibus ; femoribus cum 
