34 



common as the type ; but both the latter and the variety may be easily recog- 

 nised by their wide thorax (which is distinctly broader than long), the raised 

 thoracic side-margin, and the deep striae on the elytra. 



A. versutus. — Also has a broad raised side border to the thorax, but it is 

 smaller (3 J lines) ; the thorax is broader and shorter; and the striae on the 

 elytra are fine. The colour is the same as viduus. 



A. atratus. — Head, thorax, and elytra shining black ; legs pitchy. Length 

 34 lines. Common in damp places. Easily recognised from the other black 

 species with pitchy legs, by its thorax which is about as long as broad. 



A, micans and A. scitulus. — Both these species have the head, thorax, 

 and elytra black, with a greenish reflection, and the legs brown ; but scitu- 

 lus has the thorax distinctly narrower behind, while in micans it is nearly as 

 broad behind as in front. Both species are fairly common, and measure 

 about \ inch in length. 



A. piceus. — Head and thorax nearly black; elytra mahogany brown and 

 parallel sided ; the thorax not narrowed behind, about as broad as long. 

 Length 3 lines. Eairly common, like most of the genus, in damp places. 

 Can be easily distinguished from Thoreyi, which it most nearly resembles, 

 by the thorax not being narrowed behind. 



A. gracilipes. — Entirely black ; thorax narrowed behind. Length 3 lines. 

 The only species with small thorax and black legs. Common. 



A . fuliginosus. — Head and thorax black ; elytra ovate and pitchy ; thorax 

 narrowed behind ; legs brown. Length nearly 3 lines. Common. 



A . Thoreyi. — Head and thorax black ; elytra oblong and more reddish 

 than in fuliginosus ; thorax narrowed behind ; legs brown. Length 3 lines. 

 Not very common. 



A . puelhis. — Closely resembles fuliginosus , but the thorax is narrower, 

 and the elytra not quite so rounded at the sides ; and the insect is slightly 

 longer (3j lines). Not so common as either of the preceding. 



PTEROSTICHUS. 



The twenty -two British species of this genus vary so much among them- 

 selves, not only in colour and size but in general structure and appearance, 

 that they were classed by the less recent writers on Coleoptera under at least 

 eight different genera, viz : Abax, Adelosia, Pcecilus, Pterostichus, Argu- 

 tor, Steropes, Omaseus, and Platysma. 



In the analysis of genera it will be observed that the species of this genus 

 fall into three groups, viz. : 



a. Species of the Feronidce having the upper side black, the base of the 

 thorax as wide as the elytra, and length over \ inch - - P. striola. 



