NATURAL SCIENCES OF PHILADELPHIA. 371 



5. G. dichrous. New England. I received this species from Dr. Harris 

 as bearing the name in the Melsheimer collection ; specimens under the same 

 name are contained in Dr. Zimmermann's cabinet, now in possession of Dr. 

 Samuel Lewis. It closely resembles G. limbatus, but is a little more 

 robust, and not bronzed on the margin and suture. 



6. G. elevatus. One specimen. New York, No. 1829 Harris' collection. 

 Very distinct by its more convex elevated body, more strongly attenuated 

 at each end, and by the much coarser punctures of the outer elytral rows. 



7. G. consobrinus Lee. Ann. Lye. Nat. Hist. New York, v, 209. 

 Abundant in California, at San Francisco, Mendocino, &c. 



8. G. p 1 i c i f e r iec, ibid. California, not abundant. Easily known by 

 the reflexed edge of the elytra being interrupted near the tip by a slight de- 

 pression, so that the appearance of a small fold is produced, extending from 

 the small depression to the apical truncation. I received from Mr. A. Murray 

 a smaller specimen, which agrees sufficiently with the description of G. mar- 

 giniventris Motsch., Bull. Mosc. 1859, ii, 174, to induce me to place the latter 

 aa a synonym. 



9. G. y tM iv&Ws Kirby, Fauna Bor. Am., iv, 80 ; Aube. Hydroc. 672. A 

 common species from Pennsylvania, northward to Lake Superior; in the Zim- 

 mermann collection it is determined as G-verjlralis Kirby, but although agree- 

 ing in other respects with Kirby's description it seems generally too large to 

 be referred to the latter, which is compared with G. a e n e u s, a much smal- 

 ler species. Specimens occur in which the under surface is chestnut brown, 

 with the inflexed margins, the sides and tip of the abdomen and the legs 

 paler ferruginous; G. limbatus J Aub<i, 670 (nee Say), is considered by Dr. 

 Zimmermann to belong to this species. 



10. G. a q u i r i s. Middle States ; differs from the preceding in the narrower 

 form, and more squarely truncate elytra ; the under surface is darker brown, 

 in one specimen nearly black, with the inflexed margins, sides and tip of 

 abdomen, and feet paler ferruginous ; it is less elongate than the next species 

 aad the pale color of the sides of the ventral segments is not arranged in 

 spots but is diffused. On account of the more sudden truncation of the tips 

 of the elytra I would refer G. limbatus J Aube to this, rather than to the pre- 

 ceding species. 



11. G. maculiventris. Abundant at Lake Superior; one specimen 

 from Montana; more elongate than usual, and easily recognized by the dark 

 brown color of the under surface, with well marked pale triangular spots 

 each side on the ventral segments. 



12. G. a f f i n i s Aub£, Hydroc. 669. New York to Lake Superior ; I have 

 also two specimens from Middle California. Our largest species, easily dis- 

 tinguished by the upper surface of both sexes, (not alone of the (^ as men- 

 tioned by Mr. Aube), being covered with very fine lines, producing under a 

 high lens an aciculate appearance. I received from Dr. Harris one speci- 

 men as No. 819 var. G. limbatus Say., teste Say, but its much larger size, as 

 well as the dark bronzed color of the greater part of the under surface, com- 

 pletely separate it from that species. 



13. G. parens Say, Trans. Am. Phil. Soc, iv, 448; ed. Lee. ii, 562; 

 Aub^, Hydroc. 701. Two specimens from Texas agree with the descriptions 

 of this species ; they differ from the other small species having the under 

 surface black bronzed, by the more coarse punctures of the elytral rows, the 

 outer ones of which become, by the approximation of the punctures, slightly 

 impressed. 



14. G. p'icipes Aube, Hydroc, 694; Mannh. Bull. Mosc. 1843, 223; 

 ibid., 1853, ii, 164. Alaska and Oregon. I have three specimens collected 

 in Labrador, one of which does not seem to differ from the types from Alaska 

 kindly sent me by Baron Chaudoir and Count Mnizech ; in one of the speci- 



1868.] 



