MEMOniS OF THE NATIONAL ACADEMY OF SCIENCES. 



181 



liodv now increases in width 



- cT 



End of body "f cT l>np3 "f 

 Siimmcrista alht.frans (sliaip- ti>utliL-(l 

 luiin). 



Fonrlh staqc, after iJie third molt. — Length, 30 nini. The niaikings and colors are the same 



as in Stage V, but the hirva at this period only (lifters from the third stage in being longer iu 



ju-ojioition, though with a greater number of black lines and spots, as described under the last 



Stage. 



Fi/'th and last stof/c' — September 12. Length, 40-50 mm. The 



fri>m tlic prothoracie segment to the eighth abdominal, the head 



being much rounded, but a little wider than the prothoracie segment 



and more pitchy red. Tlie arrangement of the markings is mainly 



as in the third and fourth stages, but the straw-yellow bands are 



now deep orange, often almost coralred. The number of blackish 



lines have increased. There are five instead of three dorsal lines, 



the outer line on each side being the heaviest and most continuous 



and scarcely broken at the sutures. The black spots and slashes 



on the sides at the base of the abdominal legs are more distinct and 



numerous than before, as ;!re the black spots on the eighth, ninth, 



and tenth segments, behind the dorsal hump. On the hinder edge 



of the eighth segment are eleven black spots, varying iu size and 



shape. On the ninth segment are three sublinear dorsal and two oblong black lateral spots, and 



on the tenth segment are tluee dorsal coarse black dots, and on each side a black dot and oblong 



black spot. The supraanal plate is distinct, crescent-shaped, and deep honey-yellow, like the anal 



legs. There is a median ventral, interrupted black line, also 

 indicated in the third stage. 



Iu this genus, then, we have a retnin to the functional 

 anal legs, armed with hooks, the end of the body not being 

 more or less permanently uplifted or extended hcnizontally. 

 Instead of this deterrent or terrifying feature we have the 

 showy coral-red hump and the bright black and red bauds on 

 a shining, glistemug skin (already indicated as early as the 

 third stage), which may be danger signals to birds to whom 

 this caterpillar may be distasteful. 



Cocoon.— A thin, white, irregularly oval, tough web, 

 through which the pupa is partly visible. Beutenmiiller says : 

 "The cocoon is irregularly oval, and is of a tough, sordid 

 white texture, and is spun on the ground amongst leaves" (p. 

 2(i). Miss Soule writes me that "of five specimens, three 



spun flat circular cocoons between leaves and two pupated with no attempt at spinning." 



p„^,„._r.ody moderately stout, rather long, the end moderately blunt; the surface, except at 



the end of the abdomen, coarsely punctured, and the sutures rather coarsely sbagreened. The 



eremaster (fig. 70) is peculiar in being double or deeply forked at 



the end, each fork or spine being stout, flattened, rugose, but 



with the tip smooth, polished, and slightly directed outward. 



The spines are longitudinally ridged at the base, and transversely 



so toward the smooth tip, and the inner side bears three long 



slender setfe, curved at the ends. These setie are often broken 



oil', and their presence would not be suspected. The two spines 



vary in distance apart, being in two out of three examples closely 



contiguous, while in another specimen they are opened wide apart, 



this dilfereuce being i)robably due to dilference in contraction of 



the muscles at the time of death. Length, 17-23 mm. 



Habits. — Thisis])erhai)S the most common notodontian cater- 

 pillar to be Ibund on the oak. At first the caterpillars are gregarious, but after the hrst or second 



molt they begin to scatter over the tree. In Georgia, according to Smith and Abbot, the cater- 

 pillar "spun itself up in a thin white web between the leaves October 28, and came out on the 



Vu;. 

 anal lo; 



71. — riijia of Sttnniwrista aUiifrons; anl, 

 Xs: (T, rruluastiT .sbarp-ttintlntl lorm). 



Fig. 72 Pupa of Stimmeyisla albi/rons, 9 . 



' lieutemniiUer descriljcs six stuges. 



