LEPIDOPTERA. 323 



of feet, their very slow gliding motions, and the slug-like form 

 of some of them. In these caterpillars the body is very short 

 and tiiicU, and approaches more or less to an oval form; it is 

 naked, or, in some kinds, covered only with short down; the 

 head is small, and can be drawn in and concealed under the 

 first ring; the six fore legs are also small and retractile; and 

 the other legs consist only of little fleshy elevations, without 

 claws or hooks. The under side of the body is smeared with 

 a sticky fluid, which seems designed to render their footing 

 more secure, and leaves a slimy track wherever the insects go. 

 Their cocoons are very small, almost round, tough, and parch- 

 ment-like, and are fastened to the twigs of the plants on which 

 the insects live. The moths of some, if not of all, of the Lima- 

 codes make their escape by pushing ofl" one end of the cocoon, 

 which separates like a little circular lid. 



The most common of these slug-caterpiflars, in Massachu- 

 setts, live on walnut-trees. They come to their full size in 

 September and October, and then measure five eighths of an 

 inch in length, and rather more than three eighths across the 

 middle. The body is thick, and its outline nearly diamond- 

 shaped ; the back is a little hollowed, and the middle of each 

 side rises to an obtuse angle; it is of a green color, with the 

 elevated edges brown. The boat-like form of this caterpillar 

 induced me to name it Limacodes Scapha, the skiff Limacodes, 

 in my Catalogue of the "Insects of Massachusetts." My 

 specimens generally died after they had made their cocoons, 

 and consequently the moth is unknown to me. 



The moth of a Limacodes, called Cippus* by Sir J. E. Smith, 

 is sometimes found in Massachusetts, from the middle of July 

 till the tenth of August. It is of a reddish brown color; on 

 each of the fore wings there is a small dark brown dot near 

 the middle, and a broad wavy green band beginning at the 

 base, and bending round till it touches the front margin near 



• Probably not the true Cippus of Fabricius, which is found in Surinam. 

 There is a figure of our species in Guerin's " Iconographic du Regne Animal," 

 •where it is named Limacodes Delphinii, but for what reason I know not, for it 

 docs not live on the Delphinium or larkspur. 



