1893.1 ^"^ [Packard. 



RECAPITULATION OF THE MORE SALIENT ONTOGENETIC FEATURES. 



A. Congenital Adaptational Features. 



1. The tubercles on the second and third thoracic and the first, seventh 

 and eighth abdominal segments three times the size of those on abdominal 

 segments 2-6 ; these tubercles being already diflferentiated at birth and 

 more markedly so than in Adoneta. 



2. Head not capable of being withdrawn into and concealed by the pro- 

 thoracic segment. 



3. The tubercles each bear only three two- forked glandular setaj. 



4. The body is more cylindrical than in the later stages, and colorless. 



B. Evolution of Adaptational Features. 



1. In Stage II the form and general colors of the full-fed larva are 

 assumed. 



2. The tubercles are now armed with numerous poisonous spinules. 



Note. — From w^hat we now know of the congenital, as compared with 

 the later acquired adaptational characters of Cochliopods, it is evident that 

 tlie latter are acquired at an earlier stage than in most other caterpillars. 



Larva of Euclea querceti (H. S.) (monitor Pack.). 



The following description is based on over a dozen individuals, found 

 from August 25 to September 8 at Brunswick, Me., on the red or swamp 

 maple and the beech, most abundantly, however, on the former, and 

 alwaj's on tlie under side of the leaves. 



Last Stage. — Length, 18 mm.; breadth, 5-6 mm. 



The outline of the body seen from above is regularly elliptical, each end 

 being alike. Body with a broad dorsal, flat, plateau-like surface, not so 

 wide as the body, extending from one end to the other, and bearing a row 

 of high conical papilliform tubercles of unequal size. From this plateau- 

 like surface the sides of the body fall away nearly vertically down to a 

 slight ridge bearing long slender papuloe, and situated above the edge of 

 the creeping disk. The body is in general pea-green of two shades, a 

 lighter and darker, with a yellowish hue, assimilating it to the color of the 

 under side of the leaves of its food-plant. 



A.long the body are two dorsal rows, wide apart, of high, elongated, 

 densely spinose conical tubercles, the spinules black on the distal half. 

 Those of the first pair, situated on the second thoracic segment, are green ; 

 those of the second and third pair yellowish ; those of the third pair are 

 larger than the second, and the second than the first. All these tubercles 

 are usually reddish on the distal half. On the next five segments is a pa-r 

 of small rounded tubercles ; the first pair, situated on the second abdom- 

 inal segment, the smallest, and the third pair the largest. The ridge 

 bearing these tubercles is orange, edged with yellow. Between the sec- 

 ond and third pair of large anterior tubercles is a rounded madder-brown 



PROC. AMEK. PHILOS. SOC. XXXI. 140. L. PRINTED APRIL 18, 1893. 



