20 ADEPHAGA, [Cllvina. 



C. fossor, L. Pitchy black, Avith the margins of the elytra and the 

 suture sometimes pitchy red ; thorax nearly quadrate, broadest behind 

 at the posterior angles, disc more or less transversely strigose ; elytra 

 elongate, dilated behind middle, with strong punctured striae, the third 

 with four larger impressions ; legs ferruginous. L. 6 mm. 



Common in England and Ireland. Scotland, abundant, Lowlands. 



C. collaris, Herbst. Smaller narrower and more elongate in pro- 

 portion than the preceding; head and thorax pitchy, elytra ferruginous ; 

 head shorter and rounder ; thorax more quadrate, less dilated at the pos- 

 terior angles, and with disc smoother ; elytra narrower. The distinctive 

 characters that separate this insect, although slight, are very constant. 

 L. 5| mm. 



Local but not uncommon in England, and Scotland, Lowlands. 



DVSCKIRIUS, Eonelli. 



The species of this genus, about 125 in number, inhabit for the most 

 part temperate regions ; very few are found within the tropics ; they are 

 usually of a bronze colour, brilliantly shining, although specimens are 

 often taken of a black or dark-brown colour without any metallic tint. 

 Our species are among the smallest of our Carabidaj ; they burrow in sandy 

 places on the sea coast or on the banks of ponds or streams ; they are 

 nearly always found in company with different species of Dledius, which 

 in all stages seem to be their natural prey. 



The larva of Dyschirius thoracicus is described by Thomson (Skand. Col. i., p. 187), 

 and is figured by Schiodte (iii., PI. xviii., Fig. 17). It is about 6 mm. long, ferru- 

 ginous, with the head and upper side of thorax darker ; the head is quadrate with 

 serrated clypeus and strong mandibles ; the prothorax is quadrate, of the same breadth 

 as the head ; the whole larva is parallel-sided, the abdominal segments from the 

 seventh becoming narrower ; the conical anal appendage is about as long as the ninth 

 segment, and the cerci are very short, not as long as the anal appendage ; the mus- 

 cular impressions of the first seven abdominal segments are very strong ; the upper 

 surface of the body is depressed, smooth and shining, and covered with small erect 

 setae. The larvae, like the perfect insects, are found on the sandy shores of the sea, 

 lakes, or rivers, devouring the larvae of Bledii and Heteroceri. 



The species are very hard to distinguish in many cases ; the chief 

 points to be noticed are the shape of the elytra, whether ovate or cylin- 

 drical, the punctuation or absence of punctuation of the striae, and the 

 dentation of the exterior side of the front tibiae. 



I. Striae of elytra prolonged to apex. 



i. Anterior margin of clypeus with a central tooth 

 (distinct in male, sometimes feeble in female). 



1. Interspaces of thorax and elytra smooth ; striae 



of elytra finely and plainly punctured . . . D. thoeacicus, Mossi. 



2. Interspaces of thorax alutaceous ; striae of 



elytra strong, almost impuuctate . . . . D. OBSCUEtrs, Gt/ll. 

 ii. Anterior margin of thorax without central tooth. 

 1. Teeth on outer side of anterior tibiae indistinct. 

 A. Interstices of elytra convex ; stria3 deep, 



almost impunetate D. impunctipennis, Daus. 



