Mr. Waterhouse on Carabideous Insects. 121 



Plata. It is easily distinguished from other Patagonian Feronia 

 hitherto discovered by its comparatively depressed form, the small 

 size of its head, cordiform thorax, black colouring, and the want of 

 wings. By candle-light the elytra display a beautiful iridescence 

 (steel-blue being the prevailing colour), as in the Pterostichus 

 brunnipes or iridipennis of Stephens ; in size it very nearly agrees 

 with that insect ; but the F. cordicollis has a much smaller head and 

 thorax, and the latter is more attenuated behind. 



A specimen of this species has been sent to Mr. Hope with the 

 specific name of obsidianus, but I have not yet found it described 

 under that name. 



Sp. 4. Feronia Dejeanii, 



Fer. alata, nigra, nitida ; thorace cordato, postic^ foveis duabus 

 impressis ; elytris elongatis subparallelis, distincte striatis, in- 

 terspatiis aliquant^ convexis. 



Long. Corp. 7^ lin. ; lat. 2^ lin. 



Hab. Monte Video. 



This species resembles the Feronia Corinthia of authors, but is a 

 trifle less than that insect ; the thorax is less convex, and although 

 considerably contracted behind, is less suddenly so than in F. Corin- 

 thia ; the posterior foveae are large and shallow, instead of being in 

 the form of a deep longitudinal groove ; the elytra are distinctly 

 striated throughout, and not, as in the species last mentioned, obli- 

 terated on the outer portion of each elytron. The present insect, 

 moreover, differs in being of a black colour — there is perhaps a slight 

 trace of the aeneous tint. 



From Feronia cordicollis, which is found in the same locality, and 

 which, in the somewhat depressed form of the thorax, it resembles, 

 the F. Dejeanii may be at once distinguished by the comparatively 

 large size of its head, its possessing wings, the thorax being rather 

 less contracted behind, the posterior fovese being broad, the elytra 

 more elongate and of a more parallel form, the striae impunctate, 

 and the antennae stouter ; its size rather exceeds that of F. cordi- 

 collis, and consequently that of F. chalcea, F. assimilis, and F, 

 simplex of Dejean. 



Description. — Head large, but slightly narrower than the thorax; 

 the eyes rather prominent ; two longitudinal deep grooves are 

 situated on the forepart of the head. Thorax truncated behind, the 

 widest part very near the anterior angles, the sides not very much 

 rounded, and the hinder part much narrower than the opposite ex- 

 tremity ; the dorsal channel distinct, but not extending either to 

 the anterior or posterior margins ; the posterior fovea large, shallow, 

 and impunctate, or at least very nearly so — some very minute punc- 

 tures being discernible under a strong lens ; these foveae extend to the 

 posterior angles, and occupy nearly two-thirds of the space between 

 them and the dorsal channel. Elytra elongate, the sides nearly 

 parallel, being very indistinctly dilated in the middle; the striae 

 are rather deep and impunctate, and the interspaces are slightly 

 convex : two impressed points are observable on the second stria 

 from the suture situated on the hinder half of the elytron, and there 



