1893.] "■*■ [Packard 



back, giving a slightly quadrilateral outline to the animal in section. It 

 is pale ultramarine green, the fleshy conical spines or papulae being 

 deeper green. Of these papulae there are two subdorsal rows, ten in a row, 

 and otherwise as already described. The spinules of these papubie are 

 white at the base, with the distal end black. There is a row of lateral 

 spines similarly spinulated and of uniform size. The four pairs of square 

 spots are blackish, those of the anterior pair (on second thoracic seg- 

 ment) being rounded. They are more or less connected with dorsal 

 irregular lines and dots. On the side of each segment is a blackish ring, 

 lined within more or less distinctly with white, and enclosing a roundish 

 hexagonal green spot. 



Remarks. — The larvae of the genus Euclea are wonderfully differentiated 

 and specialized as to their papillne and surface markings, as well as colors. 

 The object of this or rather the process by which these structures and 

 markings have gradually appeared, can, so far as we can now see, only be 

 explained by supposing that they are warning structures and colors, the 

 gay colors enabling the insect to be easily seen and the forbidding spines 

 preventing their being swallowed by birds after once being detected. On 

 the other hand, the more plain, unarmed larvae of Heterogenea are in- 

 stances of protective resemblance, as their lives are saved by their exceed- 

 ingly sluggish movements and their green colors, assimilated to the hues 

 of the under side of the leaves, in which they rest, for the most part 

 nearly nnmovable. Yet why should Euclea feed like Heterogenea and 

 allies on the under side of the leaf, and not on the upper, where it would be 

 readilj^ seen ? 



Parasa chloris H. Sch. (P. fraterna Grote). 



The larva, like those of many other Cochliopods, lives on the under 

 side of the leaf of its food-plants. It often, however, begins at the end 

 of a leaf and eats down to the base ; it remains on the under side, but 

 the hood bends over so as to be seen from above, but the color, exactly 

 like that of a brown sere part of the leaf, protects it. Several specimens 

 were kindly sent me by Miss Morton, September 4. 



Full-grown Larva. — Length, 15 mm. The body is oblong, square ; when 

 seen in section it is somewhat trapezoidal, the dorsal surface being flat- 

 tened, though siill somewhat convex, s^nd one-half to two-thirds as wide 

 as the creeping disk or under side of the body. Posteriorly the body ends 

 in a long, slender, fleshy projection or " tail," which is somewhat spinose 

 and slightly forked at the end. Along each side of the dorsal area is a 

 row of short, thick, retractile tubercles which bear peculiar stout spines, 

 which are whitish, tipped with brown at the ends. Fig. 5, sp. represents 

 a part of one of these tufts of sharp spines, which are white, becoming 

 dark towards the ends ; ct., the spiny cuticle of the body, the spinules 

 being modified cuticular cells ; cV, the same seen from above. A few cal- 

 trops were to be seen. The third pair from the head is situated nearly on 



