542 On Aquatic Carnivorous Coleoptera or Dytiscide. 
prosternal process, and the breadth of the prothoracic lateral margin. All the 
variations I have observed connect more or less with what I have called the first 
form. 
Outside the limits of Australia there occur additional variations, which have no 
other claim than their geographical separation to be considered distinct species, and 
which I therefore cannot-accept as such. Thus in Tasmania there is found a form 
differing by the straighter sides of its thorax from the Australian central form, and 
it has the yellow lateral stripe of the elytra extending without interruption to the 
humeral angle of the elytra. I have seen but one individual of it, the only 
Tasmanian specimen of the species that has come before me. 
In the Philippine Islands, the Agabus semperi, Wehncke, departs but little 
from the first Australian form, but the spots on the head and front angles of the 
thorax are reduced in size, as is also the lateral band of the elytra, while on the 
other hand the two adjacent spots on the elytra have become very conspicuous ; 
the surface is very shining, and the very fine reticulation of the elytra is even more 
indistinct than in the shining first Australian form. 
In Java occurs a form similar to the first Australian form, but with the upper 
surface nearly entirely black, and with the hind legs more slender; on 
examination the anterior angles of the thorax are decidedly reddish, and the 
lateral band and adjacent spot on the elytra may be detected; the upper surface is 
very shining, and the meshes formed by the very fine scratches of the elytra are 
rather larger, and have no trace of accompanying minute punctures such as may be 
found in the Australian form. 
Another variety resembles in size, form and sculpture, the individuals from Java 
and the Philippine Islands, but has the yellow marks on the elytra formed into five 
very definite spots on each; I have seen individuals agreeing in this respect but 
differing ¢nfer se as to minor details, from the Philippine Islands, Ternate, and New 
Guinea. 
764. Platynectes daemeli, n. sp.—Ovalis, latus, subdepressus, nitidus, niger, 
antennis pedibusque rufis ; crebre subtiliter reticulatus ; prothorace brevi, cum elytris 
omnino continuo, angulis posterioribus peracutis, ad elytia arcte applicatis ; prosterni 
processu lato, fere plano, apice peracuto ; abdomine segmento ultimo ventrali in 
utroque sexu fere leevigato. Long. 7, lat. 4 m.m. 
The male differs from the female, only by a slight incrassation of the front and 
middle tarsi, and by their basal joints being furnished beneath with short glandular 
hairs. 
Though very closely approximated by the flatter and broader varieties of Dytiscus 
decempunctatus, it seems to be really distinct ; the form is yet broader, but is more 
acuminate behind, the variegation of the surface with yellow is nearly absent, the 
antennee are always shorter, and the apical ventral segment quite free from strigose 
