160 



THE YOUNG 



NATUEALIST. 



p. gracilis is easily distinguished by its 

 size, slightly over \ inch (4 lines) ; the elytra 

 are narrow and paralled sided ; the thorax 

 with a large deep depression on each side ; 

 the legs and the apex of the antennae more 

 or less red. It does not seem very common, 

 and is taken, like the two preceding species, 

 in marshy places. 



P. ollongO'punctatus. — This species is re- 

 cognised by its distinct brassy tinge ; by its 

 broad elytra, which are only slightly convex, 

 and have a row of four or five very distinct 

 impressions in the third interstice. Size, 

 slightly under half an inch. Not very com- 

 mon, and apparently more confined to woods 

 than others of the genus. 



P. vitreus ( orinomus ) — This species, like 

 the preceding, has a row of distinct impres- 

 sions (4 or 5 in number) in the third 

 interstice of each elytron, but it wants the 

 brassy tinge of that species. The thorax 

 also is broader than long, and the antennae 

 thick; whereas in oMongopunctatus the an- 

 tennae are slender and the thorax is nearly 

 square. Length about five lines. A moun- 

 tain species. 



P, aterrimis — This local species, which 

 occurs principally in the fen districts, is 

 easily distinguished from the remaining 

 species with rounded posterior angles to 

 the thorax, by its elytra, which are lotiff, 

 flat, shining, and parallel-sided. Size about 

 half-an-inch. 



P. madidus. — A very common species, 

 recognised at once by its rounded thorax 

 and by the oblong-ovate elytra {not parallel 

 sided) with only a single impression in the 

 third interstice. Size from half to three- 

 quarters of an inch. The legs vary from 

 entirely red to wholly black. 



P. (sthiops, which is generally regarded as 

 a race of P m-adidus, differs from that spe- 

 cies in having the elytra much shorter (but 

 still rounded at the sides), and the third 

 interstice has three impressions. This spe- 

 cies occurs, I believe, only in elevated situ- 



ations, as upon the mountains of Wales and 

 Scotland. 



The small species of the genus are divi- 

 sible into two groups according to the pre- 

 sence or absence of a short stria at the base 

 of each elytron between the suture and the 

 first ordinary stria. This abbreviated stria 

 is present in all the large species of the 

 genus and can well be seen in striola It is 

 known as the scutellary stria. 



(a). — Scutellary stria absent.. P, vernalis 

 and P incequalis. 



Of these two species, P vernalis is the 

 larger, measuring three lines. The elytra 

 are parallel-sided in both species ; in both 

 also the thorax has the posterior angles 

 nearly or quite right angles. In P. vernalis 

 the insect is furnished with wings and the 

 legs are pitchy, whilst in inceqnalis the legs 

 are red and the insect is apterous. P. ver- 

 nalis is very common in damp places ; P. 

 incequalis is rather local, but occurs in simi- 

 lar situations. 



(h ) — Scutellary stria present ...P. minory 

 P. strenuus, and P. diligens. 



P. minor has the apical joint of the palpi 

 truncate at the apex ; the whole insect is 

 more or less parallel-sided ; the thorax has 

 the posterior angles right angles, and a 

 shallow basal depression on each side. 

 Length, three lines. A somewhat local 

 species, occurring in damp places. 



P. strenuus and P. diligens much resemble 

 each other, and differ from P. minor in 

 being slightly smaller and not so parallel- 

 sided ; in having the thorax with a distinct 

 deep depression on each side at the base, 

 and in the posterior angles being acute ; the 

 palpi have the last joint ovate, not tiimcate 

 P. diligens, which is rather smaller than 

 P. strenuus, is distinguished from that spe- 

 cies by having the striae at the outer portion 

 of the elytra as deep as those near the 

 suture, and in having the under side of the 

 thorax not punctured ; whereas strenuus has 

 the thorax punctured at the sides under^ 



