332 MANDIBULATA. — COLEOPTERA. 



Extremely common in old decayed willows throughout the 

 metropolitan district, and in Norfolk. " Bristol." — G. Waring, 

 Esq. " Epping."— Mr. Doubleday. " Glanville's Wootton."— 

 J. C. Dale, Esq. " Very common (at Swansea)." — L. W. Dillwyn, 

 Esq. • 



Sp. 2. costatus. Saturate niger, antennis tibiis tarsisque luteo-ferrugineis, elytris 

 hneis elevatis perspicuis, thorace antice lasviter emarginato. (Long. corp. 



if-ajlin.) 



Ptil. costatus. Gyilerihal, iv. 329. — Pt. pectinicornis. var. j8. ? Sleph. Catal. 

 139. No. 1412. 



Deep satiny black: thorax with the anterior margin more or less emarginated 

 in the middle ; elytra deep black or castaneous, each with two or three elevated 

 longitudinal lines : femora for the most part and sometimes the tibise pitchy- 

 black: antennae and tarsi of a rusty-luteous ; the radii of the former somewhat 

 clavate and abbreviated in the males. 



The emarginate anterior edge of the thorax and subcostated elytra, with the 

 general darker colour, and larger size of the insect, distinguish it from the 

 other species. 



Found in willows and poplars; not so common as the fore- 

 going. 



Genus CCLII. — Ptintjs Auctorum. 



Antenna approximating at the base, elongate, filiform, composed of subcylindric 

 nearly equal articulations, the second alone being abbreviated : Palpi unequal, 

 subfiliform : maxilla unidentate at the origin of the palpi : head small : eyes 

 globose, rather prominent : thorax cucullate, generally coarctate behind : ab- 

 domen much broader than the head and thorax, suboval or globose ; legs long 



and slender ; femora (especially in the males) clavate. 



- y 



From Mezium and Gibbium, which have the abdomen ovate and 

 tumid, and broader than the head and thorax, Ptinus may be 

 known by the elytra not being soldered together at the suture, 

 by the dissimilarity in the structure of the antennae, the second and 

 third joints of which are not stouter than the others, in having a 

 distinct scutellum, &c: — the species are many of them very de- 

 structive to collections of dried plants and insects, upon which their 

 larvse subsist : the pupa is enclosed in a delicately white silken tissue. 



Sp. 1. imperialis. Oblongus,f uncus, thorace postice carinato, elytris lasvibus 

 macula sinuata-lobati, apicecjue albis. (Long. corp. 2 — 2\ fin.) 



