Sept. 1898.] Kunze : Two Forms of Cerura nivea. 189 



As before mentioned, there are two annual broods in this hot and 

 arid region. The larva feeds on willow and' Cottonwood and I have 

 collected cocoons early in spring from both food-plants. The examples 

 which served for observation, were two females taken in September, 

 1897, in Phoenix. One of these was almost immaculate, except a 

 small black spot between the veins of external border of primaries. 

 The other was marked at the base and near cell of primaries with a few 

 black patches and irregular markings. Bodies of both heavily clothed 

 by long white hair, and at first thought I had taken a Spilosoma. 

 The base of wings likewise thickly covered by a thick mass of shorter 

 hair than on the body. The males of this species have longer hair than the 

 females. These Arizona cerurines are much larger than the C. cinerea 

 of the East. After ovipositing I sent both females, a little the worse 

 for functions performed, to Professor Packard, and also better examples 

 of the spring and autumn broods of both sexes. Ground color of all 

 was snow-white. 



The first female secured I placed in a paper box for ovipositing. 

 This example regarding ornamentation, agreed more fully with figure 

 19 of Packard's Bombycine Moths, described as C. cinerea var. nivea 

 or Dyar's type of meridionalis, $ . On the night of Sept. 19th a few 

 eggs were laid and some more the following evening. They were laid 

 singly and in piles of 5 to 6 each. They were black, of a dull color, 

 hemispherical and flat at base. Size 1.5 mm. Seven larvae hatched 

 Sept. 26th and eight more Sept. 27th, between the hours of 8.30 and 

 9.45 A. M., making time of hatching seven days. 



Stage I. — Face neutral pink, pilose, the same as the rest of the body. On all the 

 joints white hairs. Joint 2 has two lateral prothoracic horns finely spinose, of purple 

 color. These processes connected by a dorsal ridge. Two subdorsal, purple stripes 

 from joint 2 to 7, interrupted on joints 8 and 9, and continued from joint 10 to 12. 

 Joint 13 has appended two anal, filamental legs or " tails." Dorsum greenish-yellow 

 in a continuous line to penultimate joint. Dorsum of segments 7, 8 and 9, presents a 

 diamond-shaped mark, due to absence of subdorsal purple stripes. Tails covered 

 with spines or spinules, annulated purple and greenish yellow. Near insertion the 

 " tails " are purple, and of timilar color at middle and terminal paits. Feet yellow- 

 ish white, almost co .colorous with body. Length of larva without stemapods, 3 mm. 

 and inclusive of these organs, 5.5 mm. The head .5 mm. in breadth, space between 

 head and middle of body .33 mm. breadth, and between joints 6 and 7, .5 mm. 



Stage II. — Observed October 3d, larva seven days old. Length of larva without 

 stemapods, 14 mm and inclusive of " tails," 19 mm. Width of joint 2, 2 mm., and 

 of joints 6 and 7, 1.25 mm. Length of prothoracic horas, I mm., width of ridge con- 

 necting these processes, 3 mm. Face and body sparingly covered with white hair. 

 Face and vertex speckled brown and green. Middle of face and mouth parts green. 



