323 



the midrib. They creep regularly, not haltingly, and move pretty fast. 

 When alarmed or disturbed they curl quickly, and loose their hold, and 

 fall to the ground. 



Body fusiform, or cylindrical and tapering at each extremity. Legs six- 

 teen, all perfect. Length three fourths, of an inch. Back dark purple 

 brown. A broad, bright yellow stripe on each side, on the line of the 

 spiracles. All beneath yellowish green. Head shining black. Two shining 

 black plates on the first i-ing. Brown portion of the second and third rings 

 with a transverse row of four black, setiferous tubercles. Remainine rings 

 to the eleventh inclusive, with six similar tubercles on the back, twelfth ring 

 with six, arranged four and two. Sides of the body below the yellow stripe 

 without two black tubercles on the side of each ring. Several minute white 

 dots arranged nearly in two rows on the back, in a line with the upper dor- 

 sal tubercles. Each tubercle produces one or two short and stiff bristles, 

 and the dorsal ones have also a white dot on each side of their base later- 

 ally. Terminal segments without a black corneous plate. 



Found the same on turnip leaves, Oct. 20, 1844, their ravages very con- 

 siderable. 



Porrectaria ? sp. 



Oct. 25-Nov. 1, 1841. Found abundantly on fences, crawling about. 



Head yellowish; first three rings sjjotted with brown ; body white ; first 

 three pair of legs long, dirty white. The prolegs very close together, of the 

 usual number, but extremely short, consisting only of little tubercles, each 

 with an oval ring of hooks. Tip of the last ring blackish. 



This larva inhabits a portable case. In moving it spins a thread, fastening 

 it at every step, so that if disturbed, and obliged to withdraw entirely within 

 its case, the latter hangs 

 suspended by the thread. 

 Length of the case quar- 

 ter of an inch. The case 

 is rather rough, appar- 

 ently fibrous, ash colored, and as tough as stiff paper. This case is cylin- 

 drical or fusiform ; the anterior end is curved downwards a little and has 

 an opening beneath. The other end is closed by three bevelled lips, meet- 

 ing In a point, and capable of being opened, when the larva Avishes to eject 

 its excrement. 



The case of this insect somewhat resembles one figured in Re'aumur's Me- 

 moires, Tome IH, p. 97, plate 7, figs. 1-3, possibly the Porrectaria anati- 

 pennella. It agrees with the description of the case of Ornix anseripennella, 

 in Duponchel's Hist. Nat. Le'p. (Nocturnes, Tom. VIII, p. 573, note), ex- 

 cept that it is not carinated, but is even on the surface, with two or three 



Fig. 46. 



