352 Mr. Waterhouse on Carabideous Insects. 



This species greatly resembles B. crepitans : its average size is 

 rather greater — the smaller specimens being about equal in size to 

 the larger- sized individuals of B. crepitans — it differs moreover in 

 having the third and fourth joints of the antennae red instead of 

 black ; the thorax is longer and less dilated in front ; the elytra are 

 rather wider, have a slight pitchy hue, their elevated ridges are 

 more distinct, and there is scarcely any trace of punctures in the 

 interstices. The body beneath is pitchy-red, the red colour most 

 distinct on the chest, and on the apical portion of the abdomen the 

 pitch colour prevails ; the four basal joints of the antennae are pale 

 testaceous, and the remaining joints are brownish ; the legs are pale 

 testaceous ; the thorax and hinder portion of the head are very de- 

 licately punctured. 



In Mr. Darwin's collection are five specimens agreeing with the 

 above description, and a sixth specimen, which differs only in being 

 considerably larger — its length is 6 lines, and width 2f lines. 



Besides these there is a Brachinus which in some respects resem- 

 bles the B. Platensis, but is probably a distinct species ; as I do not 

 however like to found a species upon a single specimen, unless that 

 specimen possess well-marked characters, I will merely call atten- 

 tion to its peculiarities. 



The four basal joints of the antenna?, the head, thorax, legs and 

 chest are red, the elytra are dull black, with an indistinct pitchy 

 hue, and the abdomen is pitchy, and an indistinct pitchy spot is ob- 

 servable on the tip of the femora. The head and thorax, as well as 

 the elytra, are impunctate, and the latter are furnished with slightly 

 elevated ridges. Length 4J lines. 



This insect differs from B. Platensis, in having the head and thorax 

 impunctate, the thorax shorter, the femora tipped with pitchy, and 

 the elevated striae of the elytra less distinct. From B. crepitans 

 (which it greatly resembles) it may be distinguished by the impunc- 

 tate upper surface of the head, thorax, and elytra, the want of black 

 on the third and fourth joints of the antennae and the dusky tip to 

 the femora ; to which may be added the dull black colour of the 

 elytra. For the present it may be called B. Platensis, var. ? 



Sp. 3. Brachinus nigripes. 



B. niger ; pectore, coxis, capite, thoraceque ferrugineis ; antennis 

 fuscescentibus, ad basin nigrescentibus ; articulis basalibus fer- 

 rugineo pictis ; elytris subcostatis. 



B. crepitante paul6 minor. 



Long. 3— 2$ lin. ; lat 1^— 1£ Hn. 



This species is a trifle smaller than B. crepitans, the head and 

 thorax are proportionately rather smaller, the elytra shorter and 

 broader, and the antennae longer ; the eyes are more prominent, and 

 the head is more attenuated behind. 



The head and thorax are red, impunctate ; the latter with rather 

 a deep dorsal channel, and two somewhat shallow posterior foveae ; 

 palpi black, the extremities of the joints reddish ; antennae with the 



