HYDROZOA. 
49 
termed gastropores, and the dactylozooids in smaller pits termed dacty- Cases 2, 4. 
lopores, the pores being usually arranged in systems (Figs. 15 and 18). 
Milleporim. Millepora forms massive laminate or branched Case 4. 
growths, and presents a great variety of forms ; but, according to Prof. 
Hickson, there are no definite specific characters separating one form 
from another, and consequently we must regard the forty or more 
so-called species as mere variations of only one species, viz., Millepora 
Fig. 10. 
alacorms, or the Stag’s Horn Millepora. He would call, for instance, 
M. verrucosa (Case 4, upright portion) if. alcicornis, facies verrucosa. 
It seems that an embryo settling down on a broad surface with 
room to spread forms a laminate growth, such as the typical if 
alcicornis or if. complanata (Case 4) ; but if it settles on a smali 
object it tends to form a branching growth. Millepora often encrusts 
old bottles, &c. ; in Case 3a a delicate network of Fan Coral is exhibited 
coated with a thin crust of Millepora alcicornis. Systems consisting 
of small gastropores, surrounded by irregular circles of about six stifl 
E 
