OBSEKVATIOXS OX PKESH-WATER POLYZOA. 121 



1, StatobJiist, 



2, Development of the Statobla.sl in the Funieulus, 



3, Devel(.)pnieiit of the Polypide in the K^Slatohlast, und 



4, ]j Lidding. 



1. Statoblast. 



The general strueture of this seed-like body, dilfei'iug in shape 

 and size in different species, is now well-known and the following 

 description refers specially to the statoblast of I'cct. gdatiiiusa. In 

 winter the dead colony is soon decomposed and the statoblasts con- 

 tained in it are set free. Dm'ing winter and spring months, they may 

 1je found on the surface of the water in large numbers, clinging to float- 

 ing logs, Ijamboo sticks or trunks of aquatic plants. They are of a 

 dark brownish color with a wide marginal zone of a lighter tinge. 



Let us take one of them and examine it more minutely. Its 

 s]i:i[)e is, properly speaking, like a flat lens. The (jutline, as it lies 

 flat, is quadrate-oblong, about 1.5 x 1.3 mm., and about U.3 mm. in 

 thickness. I may here mention that this s[)ecies has the largest 

 statoblast among all known Phylactolcomatous Polyzoa. It presents 

 double curvature after the manner of a saddle (fig. 5, PI. XA^II). For 

 conveniences sake, we may call that side on which the longer axis is 

 convex as the "conv^ex surface," and the opposite side as the ''con- 

 cave surface," although tliese terms do not hold good with regard 

 to the shorter axis. On both sides, the whole surface is beautifully 

 marked into hexao'onal areas, more distinct in the marginal zone 

 than in the central portion. The extent of the central darker area 

 is various in different statoblasts, and it may also differ on different 

 sides of the same statoblast. Generally it ranges from 0.5 mm. to 

 0.6 mm. in diameter. 



