264 On Aquatic Carnivorous Coleoptera or Dytiscide. 
]. 5.—Genus SYNCHORTUS. 
Anterior tibize with indefinite outer apical angle, with elongate curved spur ; 
antennee slender ; hind tibiz broad and fiattened. 
The six species* occur in Madagascar and tropical Africa. 
14. Synchortus simplex, n. sp.—Ovalis, sat convexus, castaneo-testazeus, nitidus, 
fere levis, elytris punctis paucis subtilissimis. Long. 2%, lat. 13 m.m. 
The single male individual, which is all I have seen of the species, has the basal 
joints of the front and middle tarsi dilated, the latter furnished underneath with a 
very large cupule. 
Africa, (Gaboon). 516. 
15. Synchortus aciculatus, n. sp.—Ovalis, sat convexus, castaneo-testaceus, 
nitidus, levis, sed elytris versus apicem et exterius punctis imbricatis sat approxi- 
matis. Long.* 2s, lat. 1g m.m. 
The only individual I have seen is a female, and differs from Synchortus simplex 
only by the tarsi and the elytral sculpture, so that I believe the two are probably 
the sexes of one species. 
Africa, (Gaboon). 517. 
16. Synchortus sparsus, n. sp.—Ovalis, sat convexus, castaneo-testaceus, nitidus, 
levis, sed elytris apicem versus et exterius punctis parvis sub-asperatis, haud 
numerosis. Long. 33, lat. 13 m.m. 
The single female I have seen of this species differs from Synchortus aciculatus, 
by its rather larger size, and the much smaller punctures on the elytra. 
Africa, (Gaboon). 518. 
17. Synchortus duplicatus, n. sp.—Ovalis, sat convexus, castaneus, nitidus, levis, 
elytris punctis paucis subtilissimis. Long. 32, lat, 2 m.m. 
I have seen only males of this species, they are extremely similar to Synchortus 
simplex but are twice the size. 
Madagascar. 519. 
18. Hydrocanthus asperatus, Fairm. Ann. Soc. Fr. 1863 p. 199.—Ovalis, sat 
* The following also belongs to Synchortus :—Noterus imbricatus, Klug, (No. 1,498, huj. op.), near 
No. 18; Eastern Africa. 
