32 SYNOPTIC COLLECTION. 



the name of Haeckelina gigantea. PI. 17, fig. i, represents 

 the young Astrorhiza which has arisen by a forcible sepa- 

 ration of a piece of the arm, it being probable that new 

 animals or zoons arise from the swollen ends of the arms. 

 It is Amoeba-like, and is without a shell. The drawing 

 represents it just after its separation ; PI. 17, fig. 2, is the 

 same ten hours later ; fig. 3, the same somewhat con- 

 tracted ; fig. 4, the same four days after separation (one 

 projection sends out a number of delicate thread-like 

 pseudopodia which branch slightly) ; fig. 5 is an older 

 stage in which the dark brown protoplasm is not yet cov- 

 ered with a shell ; fig. 6 represents one still further de- 

 veloped which appears to be on the point of making a 

 shell. The process of specialization continues until the 

 full grown organism (.fig. 7) has the shell completed. 

 The material of which it is made is usually sand or mud. 

 It has a varying number of continuations from which ex- 

 tend the pseudopodia. Fig. 8 is the drawing of a colony 

 of seven adult zoons united by their arms which in this 

 case serve as stolons. 



According to Neumayr 1 the irregular agglutinating 

 Foraminifera, such as the Astrorhizidae, have given rise 

 to the regular agglutinating forms, and these in turn to 

 the imperf orated and the perforated calcareous Forami- 

 nifera. 



Re.ophax bacillaris Brady (No. 18), and R. nodulosa 

 Brady (No. 19), are more regular than Astrorhiza, though 

 they are rough on the surface and are usually made of 

 sand with a silicious cement. 



Cornnspira involvens Reuss. (PI. 20, fig. i), is one of 

 the imperforate limy shells. It has a variable number of 

 undivided convolutions making a circular flattened shell. 

 Another species, C. striolata Brady (PI. 20, fig. 2), 

 broadens out and passes over into a form resembling 

 Peneroplis, soon to be described. 



!Die Stamme des Thierreiches, I, 1889, p. 198. 



