$52 Mr. Waterhouse on Carabideous Insecis. 
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 antennz 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 antennz 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 22 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 antenne, 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 44 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 striz 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 antennz 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. 8. Brachinus nigripes. 
B. niger; pectore, coxis, capite, thoraceque ferrugineis; antennis 
fuscescentibus, ad basin nigrescentibus ; articulis basalibus fer- 
rugineo pictis; elytris subcostatis. 
B. crepitante paulo minor. 
Long. 3— 2? lin.; lat 13}—14 lin. 
This species is a trifle smaller than B. crepitans, the head and 
thorax are proportionately rather smaller, the elytra shorter and 
broader, and the antenne 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 fovee ; 
palpi black, the extremities of the joints reddish ; antenne with the 
