MEMOIRS OF THE NATIONAL ACADEMY OF SCIENCES. 137 



prick of its spines lias no poisonous efiect whatever. Mr. Abbot tells us that this eaterpillur is 

 called in \'iroinia the hickory-horned devil, and that, when disturbed, it draws up its head, 

 shaking or striking- it from side to side; which attitude gives it so formidable an aspect that no 

 one, he affirms, will venture to handle it. people in general dreading it as much as a rattlesnake." 

 (Amer. Ent., I, p. 23n.) 



Wallace, in his "Darwinism," remarks that the green color of this larva "suggests that its 

 ancestors were once protectively colored, but, growing too large to be effectually concealed, 

 it acquired the habit of shaking its head about in order to frighten away its enemies, and 

 ultimately developed the crown of tentacles as an addition to its terrifying powers" (p. 210). 

 This is somewhat fanciful, for the caterpillars of Citheronia have not only a "crown of tentacles," 

 but similar spines at the end of the body, with smaller ones along the middle of the body, and the 

 luxuriant armature is evidently inherited from its Adelocephala ancestors. The great develop- 

 ment of the spines may, as we have suggested (Pt. I, p. 16), have arisen in resitonse to the stimuli 

 of blows on the more exposed parts of the body. 



Si'.rual differences in the larvcB of Cltlieronla, etc. — Burmeister, in referring to the larva of 

 V. h'issotii., which he considers as a variety of C. reffal/x, speaks of the caterpillar of 6'. regdlin 

 figured in Abbot and Smith as representing an individual of the feminine sex. His own figure, 

 however (PL XIX, fig. 3), is that of a male, "toujours plus petit dans ce genus." 



Parasites. — In the Loew collection of the Museum of Comparative Zoology is a large species 

 of Tachina, Bclvosia hifasclata, bred from C. reyaJi^. 



Variittions: Var. i)ifernali.'> Strecker. Head. l)ody, and legs, deep orange or l)rick-red: 

 wings above and below of the same color. Fore wings slate colored in the interspaces, onlv the 

 veins red; a large red suliapical spot near the costa, also a smaller one midway between it and 

 the inner margin. Bred from a blackish-blue larva of the usual appearance. Marylanil and 

 North Carolina. 



CITHERONIA URISSOTII (^^oi^^.lu^-;ll i. 



Ceratocampa brissotii Boisdcval, Anrmles Sue. Knt. France (4) VIII, p. .S12. 1868. — Kikby, Syn. Cat. Lep. 



Het. I, p. 742. 1892. 

 Ceratocampa rcgalis var. brtssotii Bi'rmei.ster, De.-^fr. Kep. Argentine, Lei>. Atlas, jj. 45, pi. xix, tig. 3. 1879. 



Larra. 



(PI. XVI, %. .3.) 



BurmeiMer, Descr. Rep. Argentine, Lep., }>. 4-5, .Xtla.^s, pi. xi.x, tig. 3, 1879. ( J- drawn from a dried blown 

 specimen. 1 



The figure of the larva (PI. X\'I, fig. 3) is undoubtedly drawn from a jioorly preserved 

 si^ecimen. In fact the armature of the larva? of Citheronia figured by Burmeister seems to be inac- 

 curately drawn. Burmeister states that it differs from the larva of C. Iaoc"i»i (C. i.rinn) in hav- 

 ing longer spines, though otherwise the same, while they aiv of the same orange color, with a 

 black tip. 



Three 9 9 in the Mu.seum of Comparative Zoology. i)rought by Prof. L. Agassiz on the 

 Thayer expedition, exactly agree with Boisdu\ars description. It differs from ('. mudis. to 

 which it is closely allied, in the middle series of yellow .spots being united into a continuous l)and, 

 and in the presence of a submarginal zigzag orange-red line. 



It appears to be a rarer .species than any other in Brazil. 



Fdud plant. — In Brazil, according to Burmeister. it feeds on E.nccarin liii/hmdidnxa. un 

 eiiphorbiaceous plant. 



Geocjraphicid disfrdnition. — Lagoa Santa. Cantagalli; this latter town is a few miles up in 

 the interior from Kio .laneiro. (Museum of Comparative Zoologv.) 



