RILEY A NEW OAK-GALL ON ACORN CUPS. 577 



As to the larval characters, the Geometrids have been separated 

 into two great divisions on the pedal differences that distinguish 

 Paleacrita and Anisopteryx, and while the divisions thus proposed, 

 whether by Dennis and Schiffermuller, by Samouelle or by Du- 

 ponchel, may be more or less artificial, Dr. Packard will, I think, 

 have few followers in denying generic value to the characters on 

 which they are based. 



The fact that Dr. Packard differs from me in this matter is in 

 itself of no scientific importance ; but I cannot pass unnoticed the 

 error which seems to have contributed to his decision, and on 

 which he builds a generalisation that is not warranted. The fact 

 that in certain restricted localities in New England the two in- 

 sects sometimes occur on the same tree, has had a tendency to 

 lessen the importance of their differences in the minds of some 

 entomologists. At first reluctant to admit that there were two 

 species, they still imagine the differences may prove to be dimor- 

 phic. They forget that pometaria is confined to New England,* 

 and that vernata is wide-spread through the west and south, where 

 no specimens of the other have yet been reported. 



A nezv Oak-gall on Acorn Cups. 

 By Charles V. Riley. 



The gall which Dr. En^elmann refers to in the note to p. 393 

 is an undescribed species, the only hitherto known gall on the 

 cups of acorns being the Quercus-firunus Walsh (Proc. Ent. 

 Soc. Phil. iii. p. 639, and Am. Ent. i. p. 104), a quite large (j to 

 f inch diameter) spherical, plum-like, fleshy growth, maturing in 

 autumn on both ®hiercus tinctoria and c^. rubra. It grows out 

 of the cupule, and, when fresh, is yellow with rosy spots. The 

 new gall is more or less completely imbedded in the cup, and, on 

 account of its resemblance to a diminutive acorn, I name it glan- 

 dulus. I first received it from Dr. E. Michener of Toughkena- 

 mon, Pa., who wrote concerning it, Oct. 10, 1S70: 

 "I found them this morning on the cups of <^>. bicolor Wild. I think, 

 although it was a shade tree in a field where cattle pastured, and the acorns 



* In 7th Mo. Ent. Rep. I have quoted it (p. So, note) from Dallas, Texas, on the author. 

 ity of Dr. Packard ; but I have since learned from Mr. Boll that it does not occur there, the 

 specimens which he sent to Dr. Packard being vernata. 



111 37 [Dec. 20, 1877.] 



