FAMILY ZYdJENIDJE. 37 



front. There is a subdorsal and lateral row of bright yellow 

 elongated spots, one for each ring, which are conspicuous 

 through the hairs. Thoracic legs black, abdominal legs red- 

 dish, nearly concolorous with the head. 



A few specimens in the fourth (?) stage, i. e. : that next to 

 the last moulting differed thus : They are more oblong in out- 

 line. Those hairs which in the fullfed larva were described as 

 black are here white. The mesial line of scallops here become 

 actual tufts and black in color, of which the first and last are 

 the longest. The hairs overarching the head and tip of the 

 abdomen are whitish gray. The colors of the body and the'two 

 rows of yellow spots are the same as in the mature larva. The 

 "frass" is short thick cylindrical with no markings. 



These larvae in both the stages of growth above described were 

 found June 6th, 1862, on the spears of grass, which grew in a 

 sunny place upon a high neck of land running out into Casco 

 Bay, Maine. Most of the caterpillars were feeding, a few 

 mature larvae were running about restlessly. A year after at 

 the same place but a single specimen in the fourth (?) moul- 

 ting was found May 16th. This one was kept in confine- 

 ment until July 8th. Towards the last it languished until 

 numerous Braconid larvae issued in different directions from the 

 body and spun their silken cocoons in a bunch upon the outside 

 of the larva, when it died. 



June 13th the Ctenucha larva began to construct its cocoon. 

 Early in the morning it described an ellipse upon the side of 

 the glass vessel of hairs plucked from just behind the head. 

 From this elliptical line as a base, it had by eight o'clock built 

 up rather unequalty the walls of its cocoon ; in some places a 

 third of the distance up, by simply piling upon each other the 

 spinulated hairs, which adhered firmly together. At four 

 o'clock in the afternoon, the arch was completed, and the larva 

 walled in by a light thin partition. Soon afterwards the thin floor 

 was made. No silk is spun throughout the whole operation. I 

 afterwards carefully examined portions of the cocoon under the 

 microscope, and could detect no threads of any kind. 



Four days after, the pupa appeared, and July 15th the moth 

 came out. The female laid. smooth green spherical eggs in a 

 patch, side by side upon the side of the vessel, which hatched 

 out July 28th. The young larvae were about twice the size of 

 those of Orgyia when of the same age. They had large heads, 

 and the body gradually decreased in size towards the opposite 



