456 DISCOVERY REPORTS 



absence of any distinction between the spines of the fertile and non-fertile zones, the 

 spines all being slender, and usually short, as compared with those of the typical form. 

 The ovicells are broader than is usual in the typical form and differ in their sculpture 

 (Fig. 48 C). A reticulate phase succeeds the radially striated phase, but its lines do not 



5mm 



Fig. 48. A, B. Camptoplites retiformis (Kluge). St. WS 42, South Georgia. A. Ovicells from younger 

 fertile zone showing stages in the development of the reticulation. One of the ovicells is seen obliquely. 



B. Fully calcified ovicell from the older fertile zone of the same colony. The spines are seen end-on. 



C. C. retiformis var. tenuispina var.n. St. 195, South Shetland Islands. Three zooecia with fully formed 

 ovicells. D, E. C. retiformis var. tenuispina var.n. St. 363, South Sandwich Islands. Avicularia. 

 F. C. latus (Kluge). St. TN 316, McMurdo Sound. Small avicularium for comparison with Fig. E. 



ect. edge of calcareous part of ectooecium, r. tip of a rootlet from another branch, sr. avicularian 

 scar. 



become generally and uniformly thickened as in the typical form. In older ovicells 

 nodular thickenings appear on the lines and may be accompanied by punctate sculpture 

 in the meshes. The figure shows the first indications of these thickenings. The pattern 

 of the reticulation is variable. The meshes may be fairly regular and more or less hexa- 



