370 



PSYCHE. 



[July, igo2 



preoesopliageal, why may we not have 

 in arachnids a condition in wliich even 

 the tritocerebrum has assumed this posi- 

 tion? Indeed, the acceptance of Jawor- 

 owski's work as demonstrating the pres- 

 ence of vestiges of true first antennae 

 leaves us no other alternative. 



The evidence therefore goes to show 

 that while in the insects the first pair of 

 antennae is retained throughout life, in 

 the arachnids it is the second pair which 

 is represented by the chelicerae. In 

 both groups the missing pair may be 

 present in the form of embryonic vestiges. 



Works Cited. 



1816. Savigny, J. C. Memoires sur les 



animau.x sans vertebres. 

 1829. Latreille, P. A. Les crustaces, 



les arachnides et les insectes. 

 1848. von Siebold, C. Th. Lehrbuch 



der vergleichenden Anatomie der 



wirbellosen Thiere. 

 1852. Blackwall, J. Experiments and 



observations on the poison of ani- 

 mals of the order Araneida. Trans. 

 Linn. Soc. XXI. 



1880. Balfour, F. M. Notes on the de- 

 velopment of the Araneina. Quart. 

 Journ. Micr. Sci. XX. 



1885. Pelseneer, P. Observations on 

 the nervous system of Apus. Quart. 

 Journ. Micr. Sci. XXV. 



1891. Jaworowski, A. Uber die Extre- 

 mitaten bei den Enibryonen der 

 Arachniden und Insecten. Zool. 

 Anz. XIV. 



1892. Simon, E. Histoire naturelle des 

 Araignees. I. 



1893. Viallanes, H. fitudes histologi- 

 ques et organologiques sur les cen- 

 tres nerveux et les organes des sens 

 des animaux articulds. 6e Memoire. 

 Ann. Sci. Nat. Zool. (8) XIV. 



1899. Janet, C. Sur les nerfs cepha- 

 liques, les corpora allata et le ten- 

 torium de la fourmi {Myrmica rubra 

 L.). Mem. Soc. zool. France, XII. 



GROUP CHARACTERISTICS OF SOME NORTH AMERICAN BUT- 

 TERFLIES—I. 



BY SAMUEL H. SCUDDER, CAMBRIDGE, MASS. 



Some years since I announced as in 

 preparation a Student's Manual of North 

 American Butterflies, north of Mexico, 

 and a fragment of the same was pub- 

 ished in 1892 (Proc. Amer. Acad. Arts 

 Sci., XXVII) under the title. The trop- 

 ical faunal element of our southern Nym- 

 phalinae systematically treated. Owing 



to other demands upon my time progress 

 upon this Manual has been very slow, 

 and I am now compelled to abandon the 

 project. Such few portions as are in 

 any way complete, mostly written ten 

 years or more ago, I bring together in 

 the following series of papers, in the hope 

 that their publication may be of some 



