678 On Aquatic Carnivorous Coleoptera or Dijtiscidce. 



same distance as the front one is from the front margin, and the hind one from the 

 base ; in one of Aube's type specimens, these black marks however are somewhat 

 diminished. 



Mexico. 962. 



1059. Acilius ornaticollis, Aub^, M.C. — Parum latus, nitidus, Isevigatus, elytris 

 punctis seriatis sat conspicuis, subtus rufo-testaceus, su})ra testaceus, vertice 

 thoraceque transversim nigro-signatis, elytris nigro-irroratis, pone medium fascia 

 transversa plus minusve conspicua nigra. Long. 11^, lat. 6i m.m. 



Mas, Isevigatus, nitidus. 



Fern., nitida, elytris ad basin in medio punctis elongatis sat subtilibus impressis. 



This species varies considerably in size, in the black marks of the upper surface, 

 and somewhat in the sculpture of the females. Ihe black marks on the thorax 

 consist of a transverse line very near the front margin, and of a second one just 

 behind the middle, this latter often more or less connected with a black basal 

 line ; the front line is generally slightly interrupted in the middle, and is liable to 

 be very much diminished, even broken up into three or four dashes ; the post- 

 medial mark is more or less distinctly biarcuate ; and the basal black mark is 

 sometimes quite absent. When these marks are very largely developed, the front 

 one scarcely leaves any yellow colour at the front margin, and is connected at the 

 sides with the post medial mark, and this latter may be nearly entirely confluent 

 with the black basal mark. The elytra are sometimes much more covered with 

 the black colour than at others, and the post-medial black band, never very con- 

 spicuous, can occasionally be scarcely detected. The impressed short lines on the 

 wino'-cases of the female are sometimes a little coarser, and their extension in the 

 posterior direction is a little variable, but there is never any indication of their 

 presence on the prothoi-ax. 



North America, (United States and Mexico.) 9G3. 



1060. Acilius succinctus, Aub^, M.C. — Sat convexus, nitidus, Isevigatus, elytris 

 punctis seriatis sat conspicuis, prosterno ex parte majore testaceo, abdominis lateribus 

 flavo-maculatis, supra testaceus, vertice prothoraceque transversim nigro-signatis, 

 elytris nigro-irroratis, pone medium fascia transversa nigra, pedibus anterioribus 

 testaceis, posterioribus rufescentibus, temoribus basi tibiisque extus nigricantibus. 

 Long. Ill, lat. 6^ m.m. 



Mas, nitidus, lasvigatus. 



Fem., nitida, elytris ad basin punctis elongatis rudis impressis, prothorace 

 utrinque punctis parum conspicuis. 



