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The Eggs and Larvae of Cerathosia tricolor, Smith. 

 By Geo. D. Hulst. 



About the middle of April, I received a letter from a correspondent 

 in Central Texas, telling me that he had sent by mail a box with some 

 eggs enclosed, of the much discussed Cerathosia tricolor. He was, how- 

 ever, unable to give any indicati(~)n of the food plant. When the box 

 arrived all the larvae had emerged, and the most were dead, but a few 

 still had life enough to move about, and very much to my surprise were 

 lively little Geometers ! 



The eggs are spherical, somewhat flattened, and much grooved and 

 grained. 



The caterpillars on emerging are about one-eighth of an inch in 

 length, head dark, broad, deeply indented at the summit between the 

 e\cs; front triangular with apex at indentation of summit. Mandibles 

 with 5 teeth. The eyes are marked with 8 or lo scattered hairs. 



Body cylindrical, with segments very slightly if at all swollen. Each 

 segment has, rather irregularly located, from 14 to 20 piliferous spots 

 each one with one perpendicular hair, or two divergent ones. Those 

 armed with two hairs constitute about one-third of the whole number. 

 These hau's as well as the body are dark brown or blackish in color. 



There are only six pairs of legs in all, the two anterior pairs of ab- 

 dominal legs being almo-t entirely aborted, though still evident. They 

 are however in no way used in walking, and the motion of the cater- 

 pillar is entirely geometriform, the central part of the body being fully 

 arched, and the hind pairs of legs being brought close to the pro-legs in 

 progression. 



To what extent this will clear up the systematic position of the in- 

 sect, I am unable to say. The spines are decidedly arctiiform, but the 

 existence of 12 legs only in the larva seems to put it where Mr. Grote 

 thinks it belongs, as allied to Acontia and Spraguia. The larvae of 

 Acontia have, I believe, 10 legs only. The larvae of the species of 

 Spraguia are so far as I know unknown, but the larv® of the nearly 

 allied European genus Agrophila has 12 legs and thus corresponds with 

 the larvae of Cerathosia. As far as I can learn however the larvae of both 

 Acontia and Agrophila are naked. 



I was unable to find any plant of which the larvae would partake. 

 Indeed, it is doubtful whether enough strength remained to any to live 

 even if a proper food plant had been found. At any rate the larvae were 

 not carried beyond emergence from the egg. 



