186 RHYNCHOPHORA. 
Tibize compressed, their upper margin rounded throughout; all tarsi rctractile. 
Prothorax uniformly convex, posteriorly granulate or subgranulate . . . . Dryocetes. 
TOMICUS. 
Ips, De Geer, Mém. Ins. v. p. 199 (1775); Marsham, Ent. Brit. Col. p. 51 (nec Fabr., Er.), 
Bostrichus, Fabricius, Syst. Ent. p. 59 (1777) ; Erichson, Wiegm. Arch. 11. 1, p. 62 (nec Geoffroy, 
1762). 
Tomicus, Latreille, Gen. Crust. et Ins. ii. p. 276 (1807) [nec Hist. Nat. Crust. et Ins. iil. p. 203 
(1802)] ; Lacordaire, Gen. Col. ix. p. 382; Eichhoff, Rat. Tom. p. 220. 
The synonymy of this genus is of the most. confusing character, but it cannot be 
denied that the name Jps which was applied to it by De Geer in 1775, with Dermestes 
sexdentatus, Boern. (=Ips typographus, De Geer), as type, is the name to be employed 
if the law of priority be strictly observed. ps was subsequently used for a genus of 
Nitidulide by Fabricius in the ‘ Genera Insectorum,’ a work of uncertain date, but not 
issued earlier than 1776, a year after De Geer’s publication. Fabricius also brought 
the name Bostrichus, which he had misappropriated from Geoffroy, into use for these 
Scolytids; and this name, being employed by Erichson and Ratzeburg, has obtained a 
somewhat wide currency among German writers, particularly on forest entomology. 
Tomicus, an excellent and characteristic name, is not only much later than Jps but 
was first employed in 1802 for a genus having as type ‘“ fylesinus piniperda, Fabr.” 
What the insect was that Latreille actually had before him cannot be definitely 
determined ; it must, however, have been a species of either Hylastes or Myelophilus. 
Recently, as in the last catalogue of European Coleoptera (1891), it has been 
customary to retain Hylastes, and entirely to exclude Tomicus in favour of Ips. This 
is the most satisfactory solution and, as far as the use of Jps goes, the inevitable one. 
Unfortunately the employment of Jps elsewhere in the present work (Col. II. 1, p. 387) 
makes it necessary to retain Tomicus in its ordinary significance. 
The species of Zomicus are the most important and destructive of conifer-feeding 
Scolytide ; their natural habitat is in the great conifer-forests of the Palearctic and 
Nearctic regions, outside which few species occur. Four have been found within our — 
limits. 
1. Club with sutures 1 and 2 acutely angulate . . . . . . » . . 
Basal joint of club oblong-oval, the others lunate; the sutures subcireular; 
apex of each elytron tridentate . . . . Loe eee ee ee CONCINNUS, Mann. 
2. Margin of apical excavation of each elytron with four teeth . . . . . plastographus, Lec. 
Margin of apical excavation with six teeth; posterior half of the prothorax 
with fine scattered punctuation . . . . . . %terstitialis, Kichh, 
Margin of apical excavation with five teeth ; posterior half of the prothorax 
with close subrugulose punctuation. . . . . . . . . . « « « eribricollis, Eichh. 
