142 INSECTA. 



than the following ones, is scarcely visible at the first glance, and the 

 last is most commonly terminated by a simple hook. 



They are found on the ground under the debris of vegetable mat- 

 ters ; some inhabit certain ant-hills. 



Those which have eleven joints in the antennae form the genus 



PsELAPHus, Herbst. — Staphylinus, Lin. — Anthicus, Fab. 

 In some fcAV the tarsi are furnished with hooks. 

 Chennium, Lat. 



Where the ten first joints of the antennae are almost equal and 

 lenticular, and the eleventh or last is larger and nearly globular. 

 The palpi do not project *. 



PioNix, Dej. 



Where the third joint of the antennae and the four following ones 

 are very small, transversal and granose; the eighth and three follow- 

 ing ones are thicker than those which precede them, cylindrical, and 

 as long as the first seven taken together ; the two penultimates are 

 conical and equal; the last is ovoid, elongated, pointed, and the 

 thickest of all. The maxillary palpi are A'ery salient — but shorter 

 than the head and thorax united — and consist of four cylindrical 

 joints. The labials are short, directed forwards, and consist of three 

 joints with a point at the end f- 



The others have but a single hook at the extremity of the tarsi. 



Here, the maxillary palpi, flexed or geniculated, are at least as long 

 as the head and thorax ; their second and fourth joint are much elon- 

 gated, narrowed at base, and terminated in a club. 



Sometimes the antennae, evidently longer than the head and tho- 

 rax, terminate in a club formed by the three last joints, which are 

 manifestly larger than the preceding ones, the last being almost ovoid 

 or ovoido-conical. 



PsELAPHUs, proper. — Pselaphus, Herbst J. 



Sometimes the ninth and tenth joints of the antennae, the length of 

 which, at most, is equal to that of the head and thorax, are hardly 

 larger than the preceding ones ; the eleventh or last is alone much 

 thicker, nearly spherical, and with an acicular point at the end. 



BiTHYNus, Leach. 

 Where the second joint of the antennae is mvich thicker than the 

 first, and dilated on the inner side in the manner of a tooth §. 



* Lat., Gener. Crust, et Insect. Ill, p. 77; a single species — bifuberculatum — 

 extremely well figured in the atlas of the Diet, des Sc. Nat. 



t In this family, two of the palpi at least are thus terminated. For this genus, 

 see MM. Lepeletier and Serville, Encyc. Method., Entom., X, p. 221. 



I The Pselaphii Herbstii, Hiesii, lungicollis, dresdensis, !kc. of Reichenbach or bis 

 first family of this genus ; the thorax is elongated. 



§ Ps. securiger, Ejusd. See Leach, Zool. Miscell., Ill, page 80, 82, 83, 



