OF NORTH AMERICA. 201 



median region is filled in with a dark tan colored triangular spot, its 

 apex sometimes rounded, terminating a little beyond the submedian 

 nervure. It is continued along the costa to the base of the wing (near 

 which it is deeply excavate), and terminates sharply upon the apex. 

 Externally it is lined with silver. A discoidal dark discoloration. 

 Beneath concolorous with the upper side of the secondaries, a little 

 darker at the apex (with the dark patch of the primaries faintly repro- 

 duced). The body is stouter than in the other species, while the head 

 is hardly so prominent. The costa of the primaries, which is straight, 

 becomes a little convex towards the apex, hence the apical interspace 

 is a little broader and shorter than usual. The internal angle is not 

 so well marked as in the other species." Packard, (loc. cit.) 



Expaiise of wings ^ i.io inches ; length of body, 0.50 inch. 



Hahiiat. — Massachusetts (Harris). 



Larva. — The following description is from the writings of Dr. Har- 

 ris, (Ins. Inj. Veg. p. 303). "The most common of these slug-cater- 

 pillars, in Massachusetts, 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." Dr. Harris was not acquainted with the imago at the time 

 the above description was written, as the larvae died before reaching 

 maturity ; but Dr. Packard states that Mr. Shurtleff reared the imago 

 from a larva found under a maple tree. It corresponded with Dr. 

 Harris's description, and "constructed a dense obtusely cylindrical 

 ovate cocoon on the surface of the ground, Oct. 17. It was sur- 

 rounded by an outer thin envelope, covered with grains of sand. The 

 moth appeared June 15." 



2.-LmAC0DES BIGTJTTATA. (PI. 8„ fig. 16.) 



Limacodes biguttata, Packard, Proc. Ent. Soc. Phil. HI., p. 341. 



(1864.) 

 5 . $ . — Head, thorax, abdomen and their appendages soft buflT- 

 brown ; thorax rather darker than the abdomen. 

 Primaries soft brown, crossed by a transverse, oblique, paler, whitish 



