NO. 3593 VICTORELLA — BANTA 7 



estimated by weighing portions before and after drying to constant 

 weight (at 60° C) and again after digestion of the colony in boiling 

 sodium hypochlorite. The results are as follows: 



percent 



constituent weight 



non-oxidlzable material 49.1 



water 45.4 



dry organic matter 5.5 



100.0 



The large quantity of foreign material frustrates interpretation of 

 zoarial structure. Attempts to separate the animals physically from 

 the sediment have met with failure. Perhaps the most satisfactory 

 method, suggested by Patricia L. Cook of the British Museum (Nat- 

 ural History), is to shake the material in 10 percent trisodium phosphate. 



Attempts to cultivate the animal in the presence and absence of 

 suspended calcareous material (finely ground aragonite), have failed, 

 due probably to starvation, although the animals were offered a variety 

 of diatoms and dinoflagellates at varying concentrations while they 

 were being maintained at different temperatures (10°, 15°, and 20° C). 



Because of the difficulty in isolating Victor ella argilla from its in- 

 vestment of foreign material, most of the conclusions about the zoarial 

 structure of form B have been drawn from very thick paraffin sections, 

 despite their poor technical quality. Only the examination of a 

 great number of serial sections has made an accurate interpretation 

 possible. 



The zoecia of the mature form B are exceedingly elongate, without 

 a basal dilation, and oriented perpendicular to the substrate. They 

 are closely packed so that only the rounded tips of the apertural 

 papillae and their filiform processes are visible at the surface (fig. 4). 

 Mature zoecia are so variable in length and the sections are so distorted, 

 it is impossible to estimate an average length, but the largest zoecia 

 are very long and reach deeply into the thick zoarium. It is at least 

 likely that some of the zoecia reach all the way to the substrate, 

 suggesting that the zoecia must be among the largest of the Polyzoa — 

 more than a centimeter in length. The polypides, however, are 

 much shorter (0.3 mm) and are restricted to the most superficial parts 

 of the colony. New zooids, which differ from adults only in length, 

 are produced near the zoarial surface from the lateral wall of the 

 mother zooid. In a few cases, they are produced, as in form A, 

 by the dilation of connecting tubules, but the morphology is always 

 that of form B. Form A zooids may give rise to form B zooids, 

 but the converse apparently is not true. 



The basal part of the zoarium is a poorly organized mass of zoecial 

 tubes and degenerated "stolons." In some regions the zoecia are 



