618 On Aquatic Carnivorous Coleoptera or Dytiscide. 
piceis, vertice vage piceo-maculato; corpore supra densius subtiliter reticulato, 
subtus strigosulo, prosterno piceo. Long. 14, lat. 8 m.m. 
The mate has the three basal joints of the front and middle tarsi greatly incrassate 
and but Jittle compressed, and furnished beneath with four series of large palettes, 
and with very long marginal hairs with curled extremities, they have a small basal 
patch of glandular pubescence ; the front claws are long and rather slender, abruptly 
bent at the base, and unequal, the anterior one being considerably smaller than the 
posterior; the fourth and fifth joints of the middle feet are very elongate, and 
the claws are thick and unequal, the outer one being much longer and thicker than 
the inner: the female has a small development of rugose sculpture, along the two 
outer lines of subserial punctures on the elytra. 
Europe, (Italy and Corsica). 892. 
946. Colymbetes notaticollis, Aube, Rhantus notaticollis, M.C.—Ovalis, sat 
convexus, nitidus, subtus niger, prosterno testaceo, supra testaceus, vertice nigro- 
variegato, thorace disco plaga transversa nigra, elytris creberrime nigro-irroratis, 
antennis pedibusque rufis, illis extrorsum fuscescentibus, femoribus posterioribus 
plus minusve picescentibus; elytris creberrime equaliter reticulatis : prothorace 
margine jaterali conspicue elevato. Long. 102, lat. 53 m.m. 
The male has the basal joints of the front tarsi incrassate and much compressed 
and furnished beneath with four rows of rather small palettes, the marginal hairs 
are but little developed, and their extremities are not curled; the claws are 
moderately long and about equal; the middle tarsi are clothed beneath in a manner 
similar to the front ones, and their claws are short and of about equal lengths, the 
outer being however stouter than the inner. 
The species is very similar to Dytiscus notatus ; but the entirely black ventral 
segments, and the fact that the spots of the elytra are so disposed as not to leave 
the least trace of the two vein-like yellow lines which may be generally seen in 
D. notatus, allow it to be easily distinguished ; besides this it wants the dense 
strigulose sculpture seen on the basal portion of the elytra of D. notatus, and has 
the male tarsi less dilated, their under clothing much less developed, and their 
claws shorter and nearly equal, and the side margin of the prothorax in both sexes 
more distinct: it is really much closer allied to D. bistriatus (No. 949), from which 
it is distinguished only by the black mark of the thorax being on the disc instead 
of at the base, and by the male tarsi being rather less developed. 
Europe, and Eastern Siberia, (Sweden, Finland, Northern Germany, Amurland). 893. 
947. Dytiscus notatus, Fab., Ahantus notaius, M.C_—Ovalis, sat convexus, 
nitidus, subtus niger, prosterno laminaque communi coxarum posticarum testaceis, 
abdomine maris nigro, segmentis rufo-fasciatis, feminze rufo lateraliter nigro- 
