TRir.IC XI. I'.ALANINI. 203 



finds and devours the larva 1 in tho ground beneath mil-bearing 

 trees, where a labyrinth of burrows made by the shrew in search- 

 ing for the larva' has been recorded. Davis has also noted (1007, 

 110) that the larva 1 are cnt short in their development while still 

 in the acorn by squirrels, these animals biting a small part of 

 the cnp so as to expose the base of the acorn, which is then punc- 

 tured to ascertain by the odor if there is a larva within. If so, 

 the hole is enlarged and the larva eaten, but if no larva is pres- 

 ent the sound acorn is discarded. The principal papers dealing 

 with lialaninl taxonomically are by 



Horn, <Sco. H. I'roc. Am. Phil. Hoc., XTTT, 1873, 4584(50. 

 IHuiiHuinl. Fmlericl- Pull. Br. Ent. Hoc., YTI, 1884, 107- 



108. 

 ('tixcii. 77/o*. L. Ann. N. Y. Acad. Sci., TX, 1807, 055004; 



( 1 sin. Ent. XLTI, 1010, 114128. 

 < 1 ltitl<-iHl<-n. F. H. Proc. Ent. Soc. Wash., X, 1008, 1020. 



I. BALAXIXUS Germ., 1821. (Or., "an acorn.") 



When Horn in 1873 published a synopsis of North American 

 Baltntlitus he recognized but six species. Since that time 30 addi- 

 tional forms have been described from the United States, many 

 of which are doubtless synonyms. Of these Plain-hard and Ham- 

 ilton each described one; Casey, in the two papers cited, 20, and 

 ("hittenden five. Of the 42 nominal species 20 have been recorded 

 from east of the Mississippi River. After a careful study of the 

 descriptions and a long series of specimens, we have concluded 

 that only ten of the 20 are to be regarded as really valid species. 

 Of the remaining 10, eleven are, without much doubt, synonyms 

 or mere varieties, while the remaining five have been described 

 from scanty material and without accurate information as to food 

 plants. These are difficult to recognize with certainty and are, 

 therefore, not included in the keys, but are hereafter briefly 

 1 reared without definite reference to previously described species. 

 All five are evidently closely related to ronfttxor. The ten species 

 which we regard as valid beyond doubt are for convenience sepa- 

 rated into two groups as follows: 



KEY TO GROUPS OF EASTERN I5ALAMXUS. 



a. Beak of female conspicuously longer than body. GROUP A. 



act. Beak always curved and shorter than body, or at most equal thereto; 



pygidium of male convex, hairy; all species found on oak except 



obtitsits. which breeds on hazel. GROUP B. 



