1883.] Zoölogy. 1205 
do to guess that a strongly-growing specimen with clearly self- 
sustained branches, belongs to the very variable species S. Zacus- 
trioides. If statoblasts are few or apparently wanting, the proba- 
bilities are increased. As between M. fluviatilis and S. fragilis, 
the statoblasts of the former, when present, are pretty evenly dis- 
tributed through the interspaces of the skeleton spicules, while in 
the latter they occupy, primarily, a close pavement layer upon the 
Supporting surface; and in other positions are generally grouped, 
three, four or more together, in a common envelope. 
Other species are occasionally found of a more or less massive 
character, but the majority are filmy or encrusting, rarely exceed- 
ing a few lines in thickness, though sometimes extended over 
several square feet of surface. During the summer season their 
appearance is that of more or less slimy growths in their favorite 
localities upon the under, sometimes the upper side of stones, 
roots or rotten timbers, or on Sphagnum or other water plants. 
They have little color and generally bristle with minute spi- 
cules. By the latter part of September and later, the sarcode 
of many of these colonies and often a large portion of their 
skeleton framework, will have disappeared, leaving only detached 
groups of minute statoblasts adherent to the supporting sub- 
Stance, biding their time for a new growth the coming season. 
he successes of the writer have been largely found in his explo- 
rations of such localities, and in the collection and examination 
this class of material. From a boat or while wading with rub- 
served in alcohol or allowed to dry thoroughly, otherwise they 
Will soon mold 
May be briefly stated: “ Place a few of the statoblasts upon the 
am and a cover-glass. If the statoblasts now contain bubbles 
these may generally be driven out by careful peas 
me of the most interesting and characteristic features o 
Me spoage will be disclosed. A few of the characteristic forms 0 
