CERUCHUS. 231 



136. Ceruchus atavus. (Plate XXlll, figs. 3, 4.) 



Centchufi atavus Fairm., C.R. Soc. Ent. Belg. xxxv, 1891, p. 88. 



Black and very .shining, with the antenna? and tar.si dark red- 

 Convex and rather narrow in shape, with the lei^s slijiht and 

 short, and the antennae very short. The head shining, a little 

 depressed in front, ver^'' unevenly punctured, the punctures 

 extremely coarse and confluent at the sides, fine and scattered 

 in the middle. The head widest just behind the eyes and 

 slightly narrowed in front and behind. The pronotiim convex, 

 strongly l)ut not broadly margined at the sides, and only very 

 feebly angulate, but with shai-j) hind angles, the base narrowly 

 margined and almost straight. The scutellum l)earing a few 

 punctures. The el\'-tra highly convex, with strongly marked 

 outer margins, the shoulders shaii)ly angular, the outer margins 

 nearly straight and parallel, the apical margins forming a semi- 

 circle. The surface lightly .striate, the first two dorsal striae 

 deej)er than the rest, the imiermost stria entire, the remauider 

 abbreviated beliind, the 5th and (ith also abbreviated in front, 

 the 7th and 8th verj' sliort. The striae contain fine irregidar 

 scattered punctures, and the intervals bear similar, verj' 

 irregularly scattered, punctures. The head strongly ])unctured 

 beneath at the sides. The metasternum well punctured, with 

 a deep oval impression in the middle. The abdomen strongly 

 and closely punctured beneath. 



$, The head is much narrower than the thorax. The 

 mandibles are rather long, sharj^ly pointed, with a small tooth 

 much nearer the tip than the base. The pronotuin narrows 

 a little to the front in its anterior part, the surface is fairly 

 closely but unevenly' ])unctured, and there is a transverse 

 ridge crossing the middle, curving forward a little at each end, 

 and not reaching the sides. 



cJ. The head is large, as wide as the thorax at the front 

 margin, and is strongly depressed iii its anterior part. The 

 mandibles are very shining and rather strongly punctured, 

 gently curved externally and sharjily pointed at the tij), \nth 

 a broad basal tooth internally, a strong sharj) tooth behind the 

 middle, directed upwards and inwards, and a slight conical 

 do\Aiiwardly direct e<l tooth beneatli a little beyoi\d the base. 

 The pronotum widens from the base to the front margin and is 

 smooth above, with very scattered punctures. Tlie front 

 tihiir are slightly elongate in the male, and tlie tarsi also are 

 a little longer than those of the female. 



Variation of the male. In the smallest specimen I have seen, 

 the prothorax is scarcely wider in front than at the base, the 

 head is of the same width and lias a small rugose area on each 

 side. The mandibles are about as long as the head. In the 

 largest specimen the i)rothorax is much wider in front than at 



