NATURAL SCIENCES OF PHILADELPHIA. 229 



twice as broad, though the first of them is broader than the other two, and 

 is somewhat triangular in form ; the antennae are but 9-jointed, the seventh 

 joint, which is conspicuous iu the other species, being probably the one 

 which becomes obsolete. The eyes are larger and more prominent than in 

 the specimens of the other species before me, which are females ; the under 

 surface of the head, as in them, is coarsely punctured at the sides, and finely 

 rugose longitudinally in the gular space. 



SITODREPA Thorns. Skand. Col., v. 166, (1863.) 



Synonym. Anobium Zee, Class. Col., 204. Anobiura, subg. A r t o- 

 b i u m Muls. and Rey., Col. France, Terediles, 114. 



This genus contains but a single species, which has been introduced from 

 Europe in flour, bread, and other articles of commerce, to all parts of the 

 globe. As it is the most common and the best known species of the Fabri- 

 cian genus Anobium, I preferred, in separating the genera, to retain the 

 original name for this one. It has, however, since been designated by a dis- 

 tinct name in the excellent treatise of Thomson, above cited, and is, more- 

 over, no more entitled to be regarded as the type than any other of the spe- 

 cies chosen by Thomson, Duval, or Mulsant; under these circumstances, I 

 think it proper to adopt the generic name proposed by Thomson. 



The genus will be readily recognized by the moderately stout form, and the 

 nearly contiguous anterior coxa?, which are conical and prominent; the mid- 

 dle coxae are but slightly separated by the obtusely triangular mesosternum ; 

 the metasteruum is finely channelled; the segments of the abdomen are free, 

 and the plates of the hind cox* moderately dilated inwards. The elytra are 

 finely striate, and the striae are punctured ; the outer striae are deeper, and 

 the margin near the base is somewhat prominent. The antennae are 11-joint- 

 ed, rather short, with the last three joints together about equal in length to 

 the others in the female, but longer in the male. The tarsi are narrow, with 

 the joints gradually decreasing in length, the fifth is not slender. 



1. S. p a n i c e a Thorns., Skand. Col , v. ICO ; Dermestes pan. Linn. ; Anobium 

 pan. Fabr., &c. ; Anobium (Artobium) panum Muls. and Rey., Col. France, Tere- 

 diles, 114. 



An. tenuistriatum Say, Journ. Acad. Nat. Sci., v. 173 ; Ent., (ed. Le Conte,) 

 it. 288. An. obemm iMels., Proc. Acad. Nat. Sci., 309. 



Common throughout the United States and Canada; found also in Lower 

 California, at Cape San Lucas, by Mr. Xantus. The sides of the thorax are 

 distinctly serrate. 



CTENOBIUM, n. gen. 



Body slender, cylindrical ; prothorax deeply excavated beneath for recep- 

 tion of head, which is received in repose upon the anterior coxa;. Antenna 

 1 1-jointed ; first joint thicker, nearly cylindrical ; second smaller and shorter ; 

 third equal in length to the second, triangular, about as broad as its length 

 in the female; fourth to eighth transverse, with the outer angle acutely pro- 

 longed in the female, with the fifth and seventh more prolonged than the 

 others ; in the male the third to eighth joints are prolonged externally 

 into a cylindrical branch, twice as long as the joint itself; the ninth and 

 tenth joints are compressed, elongate triangular, and as broad as the pro- 

 longations of the preceding joints ; the eleventh joint is long, oval, and com- 

 pressed ; the three last joints together are equal in length to all the preceding 

 united, in both sexes, and are much longer in the male than the female. 

 Prosternum narrowly separating the anterior coxa?, which are conical and 

 prominent; middle coxas narrowly separated by the mesosternum, which is 

 obtusely rounded behind; metasternum deeply channelled behind; hind 

 coxae with the plates narrow, nearly parallel, not dilated inwards; tibiae 



1865.] 



