194 



HANDBOOK OF PROTOZOOLOGY 



The form of the test varies greatly. In some there is only 

 one chamber, composed of a central body and radiating arms 

 which represent the material collected around the pseudopodia, 

 as in Rhabdammina (Fig. 74, a), or of a tubular body alone, as 

 in Hyperammina (Fig. 74, d). The many-chambered, or poly- 

 thalmous, forms possess tests of various spirals. The first 

 chamber is called the proloculum. It may be formed either by 

 the union of two swarmers or by asexual reproduction (Fig. 73). 

 The former is ordinarily small and known as the microspheric 

 proloculum (c), while the latter, which is usually large, is called 

 the megalospheric proloculum (g). To the proloculum are added 

 many chambers which may be closely or loosely coiled or not 

 coiled at all. These chambers are ordinarily undivided, but in 



/ V'^-w..--^ 



Fig. 74 



a. Rhabdammina abyssorum. X5 (After Kiihn). 



b. Rhizammina algaeformiSyiragment o{. X 14 (After Cushman). 



c. Saccammina sphaerica. X8 (After Rhumbler). 



d. Hyperammina subnodosa. X4 (After Brady). 



e. Ammodiscus incertus, megalospheric and microspheric forms. 

 X20 (After Kuhn). 



f. Silicina limitata. X 13 (After Cushman). 



g. Reophax nodulosus. X3 (After Brady). 



many higher forms they are divided into chamberlets. The 

 chambers are delimited by the suture on the exterior of the test. 

 The septa which divide the chambers are perforated by one or 

 more foramina known as stolon canals, or passages, through 

 which the living protoplasm extends throughout the chambers. 



