On Aquatic Carnivorous Coleoptcra or Dijtiscidw. 651 



1008. Hydaticus cinctipennis, Aube, M.C. — Ovalis, eloiigatus, subtus nigro- 

 piceus, capite prostenioque rufescentibus, supra capite thoracequc rafis, hoc basi in 

 medio indiscrete infuscato, elytris piceis, vitta hunierali longitudinali elongata, 

 paulo obliqua antice margiuem attingente lateribusque |)arum discrete rufescentibus, 

 antennis pedibusque anterioribus rufis ; pedibus posterioribus picescentibus, ungui- 

 culo interno quam externo duplo longiore. Long. 131, lat. 71 m.m. 



1 have seen only a single individual of this species, it is a male in very mutilated 

 condition, the middle tarsi are broadly dilated, but their basal patch of dense rough 

 pubescence is rather small though quite distinct. 



Though rather similar to H. modestus, the species is readily distinguished from 

 it by the less variegate colour of the upper surface. 



North America. 103G. 



1009. Hydaticus americatius, n. sp. — Oblongo-ovalis, parum latus, subtus nigro- 

 piceus, prosterno capiteque in medio testaceis, supra capite thoraceque rufo-testaceis, 

 illo in vertice nigro rufo-bimaculato, hoc basi in medio nigro, elytris vittis longi- 

 tudinalibus nigris, a vittis flavis fere integris divisis, margine laterali fasciaque lata 

 transversa basali flavis, antennis pedibusque quatuor anterioribus rufis, tibiis 

 intermediis rufo-piceis ; pedibus posterioribus piceis, unguiculo interno quam externo 

 duplo longiore. Long. VSh, lat. 7t m.m. 



The female of this species has the elytral apices distinctly produced, and sinuate, 

 but it is without any sexual sculpture on the thorax or elytra. The male is unknown 

 to me. 



This species is very closely allied to Dytiscus stagnalis (No. 1011), and is about 

 as long, but is narrower and of more parallel form, and the yellow lines and fascia 

 of the elytra are a little more distinct and definite, the female has the apices of the 

 elytra produced and no sexual sculpture. 



North America, (Red River). 1035. 



10 !0. Hydaticus hevipennis, Thoms., Op. Knt. Ill, p. 324. — Ovalis, parum latus, 

 subtus nigro-piceus, prosterno capiteque in medio testacei,s, supra capite thoraceque 

 rufo-testaceis, illo m vertice nigro rufo-bimaculato, hoc basi in medio niarro, elytris 

 nigris tsiscia sub-basali transversa parum discreta, margine laterali lineisque 

 tenuibus lougitudinalibus obsoletis, testaceis ; antennis jjedibusque quatuor anteri- 

 oribus rufis, tibiis intermediis rufo-piceis ; pedibus posterioribus piceis, unguiculo 

 interno quam externo baud duplo longiore. Long. 12^, lat 7 m.m. 



The female of this sj^ecies has the apices of the elytra at the suture a little 

 produced so as to give rise to a conspicuous sub-apical sinuation ; it has impressions 

 on the thorax and elytra as in the corresponding sex of Dytiscus stagnalis. The 

 male is unknown to me. 



TRANS. KOV. DUU. SOC, X.S., VOL. II. 4 P 



