MEMOIRS OF THE NATIONAL ACADEMY OF SCIENCES. 55 



The spurs differ very considenibly in the dirt'erent species of Adelocephala; in A. mojitesuma 

 and .1. ■'<i(h<in<fuJiif<( the spurs are lont;; and wide; in the former species al)ont oncdialf as wide as 

 long; in .1. xiihanduhtid not quite so wide. 



In ^1. hlcolor and A. alholini'nta the spurs are of the shape of those in Syssphinx and Anisota, 

 beino; narrow and sharp, lanceohite oval. In Anisota lur^/inhniKis tiiey are onediaif as lonj^- as 

 tlie til)ia. and very bhint at the end. They are also obtuse in ^1. Kfigma, but ditiei- in sliape. In 

 A. senatorla they are narrow, acute, and over one-half as long- as the til)ia. In ^1. nihiciinda they 

 are a little over one-half as lony and ditl'er in shape. It thus ajjpears in the genus Anisota to 

 aflord specific differences. 



In Eudex imperialis (PI. XXXVI, tigs. 21, 21«) the spur is remarkably broad and short, 

 being nearly as broad as long, and one half as lon^- as the very short fore tibia. ' 



In Citht't'onia rcgallfi they are much smaller and narrower, but in C. ■sepu/cralis, in which the 

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

 tibia?, generically different from those of ( '. n'r/alis. It thus appears that the length of the spur 

 accoi'ds witli and is conditioned by 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 Miiller, Brauer. Kedtedbacher, and Haase that the costa is only a 

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

 was weakened b\' 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 l)e 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,* who conclusively and very clearly 

 proves that the costal edge of the wing is in the pupa state supplied b}' a branch of the radial 

 trachea, as shown in his figure. 



Indeed, it appears from a quotation from Speyer (1870) that that lepidopterist observed in a 

 great number of Ileterocera, and also in the Phryganeida', the costal vein, " with a very clear 

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

 of Heterocera, as SlpJiin.v j)inastri, it is the "strongest tracheal branch of the w'ing." Spuler's 

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

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



Enderlein clearly shows that the veins of eacli wing belongs to two geneticallv entirelj' dif- 

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

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



SCHEME OP THE FOKE WING OF A LEPIDOPTER. 



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

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

 as suggested by Grote). 



"On some wing structures in Lepidoptera, London, 1901. 



6Eine einseitige Hemmungsbildung bei 1901. Telea polyphemus von ontogenetischen Standpunkt. Zool. 

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



