160 COE 



is consequently narrower than where the head is more fully extended. 

 The line separating the white color of head from the purple of body 

 is as sharp as possible. Ventral surface of same general color as the 

 back, but somewhat paler and with a more reddish tinge ; often with 

 a much paler median band anteriorly. Color of ventral side of head 

 whitish, separated abruptly from body color on a line corresponding 

 to a similar line of demarcation on dorsal surface. Some of the purple 

 individuals become reddish brown in intestinal region. 



Variety bicolor (pi. xvi, figs. 8, 9). Head whitish with tinge of 

 brown, with broad, triangular dorsal marking of dark brown. This 

 marking is widest behind, with its obtuse apex in the median line 

 anteriorly. Behind the head the color of body abruptly changes to 

 deep rich brown, with a narrow median band of white. The brown 

 color is deepest along the borders of the median white band, and is 

 much paler laterally ; toward the lateral margins of body it becomes 

 pale brownish, and this color continues to the ventral surface, becom- 

 ing gradually paler toward the median line. The ventral surface is 

 therefore pale brownish, and this color continues on the ventral side of 

 the head. 



The third variety, pallidum (pi. xv, fig. 7), is much less deeply 

 colored than those above described, and has a much narrower marking 

 on the head. The marking is of the same deep brown color as in the 

 other varieties, but is often less than one third as wide as the head. 

 It is commonly acutely triangular with its pointed apex in the median 

 line anteriorly. In this variety the ocelli are situated about half-way 

 between the narrow marking and the margins of the head. The 

 general color of head is whitish with a faint tinge of brownish. The 

 whole body back of the head is of a pale brownish or buff color, or it 

 is occasionally whitish with a faint tinge of brown. Oftentimes a 

 paler, or whitish, line extends longitudinally on the dorsal surface, 

 sometimes reaching posterior end of body. Ventral surface in this va- 

 riety is pale buff throughout. The red blood vessels are naturally 

 more conspicuous than in the darker varieties. 



A variety which occurs on piles at San Pedro is deep flesh color 

 with tinge of orange dorsally, and with dark brown cephalic mark- 

 ing. Ventral surface is grayish. 



Another variety, common on the piles at Monterey, is shown in pi. 

 xvi, figs. 6, 7. In this the head is opaque white with a moderately 

 large wedge-shaped dorsal marking of dark brown color on head. 

 Back of head and throughout body the color is reddish brown, 

 thickly sprinkled with minute dots of darker color. Ventral surface 



