MEMOIRS OF THE NATIONAL ACADEMY OF SCIENCES. 55 



The spurs dili'er very tonsiderably in the ditierent species of Adeloeephala; in A. montezuina 

 and ^1. suhangulafa the spurs are long and wide; in the former species about one-half as wide as 

 long; in A. suhangulata not quite so wide. 



In A. ilcolor and A. alholineafn the spurs are of the shape of those in Syssphinx and Anisota, 

 being narrow and sharp, lanceolate oval. In Anisota lurginimxis they are one-half as long as 

 the tibia, and very blunt at the end. They are also obtuse in A. stigma, but differ in shape. In 

 A. senatoria they are narrow, acute, and over one-half as long as the tibia. In A. ruhicunda they 

 are a little over one-haH as long and differ in shape. It thus appears in the genus Anisota to 

 afford speciiic differences. 



In EacJes imperialis (PI. XXXVI, figs. 21, ^2\a) the spur is remarkably broad and short, 

 being nearly as broad as long, and one half as long as the very short fore tibia. 



In Citlieronia regalis they are much smaller and narrower, but in C. sepulcralis, in which the 

 tibia is much longer than in ('. regalis, the spurs are also large and long; thej' are thus, like the 

 tibia;, generically different from those of (.'. rcgalis. It thus appears that the length of the spur 

 accords with and is conditioned l)v that of the tibia. 



XVI. THE NOMENCLATURE OF THE VEINS OF THE LEPIDOPTERA. 



In Part I of this monograph (p. 84) we adopted Spuler's nomenclature, assuming that he 

 was correct in supposing with Midler, Brauer. Kedtedbacher, and Haase tiiat the costa is only a 

 thickening of the edge of the \ying, and not a vein having a trachea for its origin. This view 

 was weakened by Chapman's" discovery of a marginal vein, which he claims is a normal con- 

 stituent of all lepidopterous wings, a marginal trachea "■ occurring during the development of 

 the wing, and often to be discovered in the perfect wing,"' where it exists as a hollow tube, and 

 carrying like the other veins sensory hairs or bristles. 



The whole question as to whether the costa represents or contains a true vein has now finally 

 been set at rest by the investigations of Dr. G. Enderlein,* wlio conclusively and veiy clearly 

 proves that the costal edge of the wing is in the pupa state supplied by a branch of the radial 

 trachea, as shown in his figure. 



Indeed, it appears from a quotation from Speyer (l8To) that that lepidopterist observed in a 

 great number of Ileterocera, and also in the Phryganeid.e, the costal vein, " with a very clear 

 lumen, sometimes the strongest vein of the whole wing." Enderloin adds that in certain stages 

 of Heterocera. as Sj>/ii)M j>i/i<t^tri, it is the '"strongest tracheal branch of the wing." Spuler's 

 failure to detect the costal vein was, remarks Enderlein. due to his not following far enough into 

 the interior of the body of the pupa to where it branches off' from the main tracheal radial trunk. 



Enderlein clearl_y shows that the veins of each wing belongs to two genetically entirelj' dif- 

 ferent systems, which he designates as the radial wing-trunk and the median wing-trunk. His 

 scheme we quote, adding the luuubers in Roman numerals in a separate column. 



SCnEMK IIF THE FORE WING OF A LEPlDOPTEIi. 



Costa 1 branch 



Radial trunk jSubcosta 1 Ijranch 



1 Radius 5 branches 



fMedia :i branches 



CuViitus 2 Ijranehes 



Median trunlv Analis 1-2 branches ( atropliied) 



1 Axillaris n)raiu-Ii 



(2 Axillaris l-IJ branches (branches atrophied) 



Enderlein shows that the discocellular veinlets, i. e., the hitherto siqaposed two veins closing 

 the discal cell are formed b^' one or two veinlets arising from the cubital 1 (not from the median, 

 as suggested bj^ Grote). 



«0n some wing structures in Lepidoptera, London, 1901. 



''Eine einseitige Henimungsbildung bei 1901. Telea jiolypbeiiius von ontogenetischen i^taiidpunkt. Zool. 

 Jahrb. Arth. fiir Anat. Bd. xvi, Jena, 1902. 



