WELLMAi;: A STUDY OF THE PROTHORAX OF BUTTERFLIES. 14I 



forming a broad band above the coxje. A portion of the ventral part of 

 the sternum is almost vertical; it is densely set with broad scales and 

 the head fits closely against it. The episternum becomes narrower on 

 the sides until it coalesces with the proscutum and is concealed by the 

 overlapping membrane. 



Ei/daiiuis tityn/s \% a typical species of ^ * ^^ ^^^ 



the last group. The prothorax is broader <£__.- - ^^— v5^ 



than in the Lyciciiidtv but not as prominent 

 as in the other groups. The lobes are upright, much compressed, almost 

 scale-like in appearance, and fold back over the rest of the pro- 

 thorax. They are light colored and consist of two thin upright walls 

 arising from a narrow base. They are somewhat broader at the apex 

 than at the base. The two lobes are widely separated by the scutel- 

 lum which occupies about a third of the dorsal space. The scutellum 

 is triangular in shape, light brown in color, and is divided by a me- 

 dian furrow into two sliglitly tumid lobes; the scutellum does not 

 extend caudad beneath the mesothorax but terminates as two lobe- 

 like sclerites which are very narrow but extend across the whole 

 dorsal surface just in front of the mesothorax; they have a slight 

 median ridge and are finely punctulated. Back of these lobes the pro- 

 thorax presents a simple membranous appearance; the narrow spaces 

 between the two sets of lobes, is also of a simple membranous char- 

 acter. The sternum is cresent-shaped but with a narrow posterior 

 projection between the coxa\ The suture between the sternum and 

 episternum is very e\ident, the episternum appearing as a tumid oval 

 sclerite reaching well up on the dorsum. 



The scales covering the prothorax are very large and fan-like, nearly 

 as large as the scale-like lobes, and are set so closely together as to 

 make it almost impossible to remove them without removing the scales 

 with them. 



There is but little variation in this last group and it shows through- 

 out a marked likeness to the prothorax of some of the moths, espe- 

 cially to the Sphingidce. 



The sphinx moth, Hciiiaris, fig. IX, has 

 the frontal lobes delicate and scale-like, -.:;=^^'*^-:^^!^fer^''H-.-^ n 



the scutellum small, triangular and only 

 slightly raised above the membranous part; 

 it does not separate the lobes as widely as in Eudainus iitynis the sec- 

 ond set of lobes differ from those in Eudamiis in being almost as high 

 as the frontal lobes and of the same scale-like character; the space 

 between the two sets of lobes is much narrower than in Eudainus. 

 The sternum and episternum present the same structure, the episternum 

 is larger and extends below the suture between it and the sternum. 



