158 CALIFORNIA ACADEMY OF SCIENCES. [Proc. 3D Ser. 



and that the lower lip of the cloacal orifices is colored 

 black instead of yellow. In the same family, however, 

 there were several colonies very similar to fig. 8 in every 

 way except that they had no white coating and the lower 

 edges of the cloacal orifices were yellow. 



Botryllus marionis Giard, 1872, p. 630, PI. XXX, figs. 

 I and 2 : 

 Figure 8 without the white coating would have nearly 

 the color of a form intermediate between Giard 's varieties 

 a and yS. Figure i represents a colony that had much 

 resemblance to variety a, especially when, as often hap- 

 pened, the general tone became more brown, and the 

 anterior part of the zooids was more yellow. 



Botryllus calendula Giard, 1872, p. 623, PL XXVII, 

 figs. I and 2 : 

 Figure 2 resembles Giard's description and figures 

 closely. Even if my figure 2 and Giard's figures had 

 been taken from the same generation of zooids in the 

 same colony, the likeness could not have been absolute; 

 for Giard's figures show only degenerating zooids and 

 young zooids that have not yet united to form systems, 

 while fig. 2 in this paper represents adult zooids. The 

 absence of distinct color markings in both is quite notice- 

 able, especially as it is not common. The condition 

 represented in fig. 2 was produced by the unfavorable 

 conditions of the aquarium in a colony normally resembling 

 fig. I, but with more of the yellowish color, like fig. 8. 

 The fact that in Giard's figures the younger generation of 

 zooids is nowhere more numerous than the older, points 

 toward the conclusion that here, too, the conditions were 

 unfavorable. 



Botryllus rubens Alder & Hancock (Alder, 1848, p. 204). 

 Figures 2, 4, and 5 agree well with the description, fig. 4 

 especially so. 



Among the variations of Family I, then, we have zooids 

 whose colors correspond to four described species. Family II 



