CAMPTOPLITES 455 



they have come to one, or (as in the fourth branch in the figure) have grown rather 

 deviously towards one. It is difficult to see whether there is any continuity of living 

 substance through the rosette-plate, but where the tissues are abundant their arrange- 

 ment suggests that there is. Similar connexions of rootlets and runners with rosette- 

 plates have been seen in Camptoplites latus (Fig. 47 I, J), C. reticulatus, C. asymmetricus, 

 C. atlanticus, and C. rectilinearis. In C. atlanticus the attaching rootlets of young colonies 

 are connected with the rosette plates of the supporting colony in the same way (Fig. 40). 



The small avicularia are short in proportion to their height, with the front and back 

 of the head almost parallel, and the lower head-angle about 90 (Fig. 47 D, F). They 

 vary in size within the colony, some being very small indeed. 



The large avicularia vary in size and shape (Fig. 47 A-G) within the species as under- 

 stood here, those from South Georgia (Fig. 47 A, B, E) being more slender and usually, 

 but not always (Fig. 47 B), flatter dorsally than those from the Palmer Archipelago and 

 Ross Sea. It is perhaps worth noticing that the large avicularia of C. asymmetricus 

 (Fig. 55 C, E), particularly of the South Georgian specimen (Fig. 55 E) are more 

 slender and less curved than those of C. areolatus, the related species from further south 

 (Fig. 55 A), and that the large avicularia of the South Georgian C. latus var. aspera 

 differ similarly from those of typical C. latus and C. latus var. striata which are found in 

 more southerly Antarctic localities (cf. Kluge, 19 14, text-fig. 20, and my Fig. 49 E, F). 

 In a specimen of C. retiformis from St. 190 (Palmer Archipelago) the large avicularia are 

 unusually large and numerous. This specimen has no ovicells. 



In the specimens from the Ross Sea region and the Palmer Archipelago the ovicells 

 are usually rather narrow in proportion to their height, and the meshes of their reticulate 

 sculpture are large and regular (Fig. 48 B). In the specimens from South Georgia they 

 are more variable, some tending to be broader with less regular reticulation, though 

 others are more typical. In these ways the South Georgian ovicells approach those of 

 var. tenuispina (Fig. 48 C), but they always show the rather regular reticulation of the 

 typical form over part of their surface ; the sculpture, when complete, is thick, as in the 

 typical form; and there are stout spines on the fertile zooecia. 



Among the specimens from St. 1660 (Ross Sea) there are some with broad branches 

 composed of as many as fifteen series of zooecia. 



The ancestrula of C. retiformis is described above, p. 438 (species 5). 



Calvet's figure of his supposed C. reticulatus (1909, pi. i, fig. 3) might well represent 

 C. retiformis, but as he attributes it without comment to a biserial species, it is to be 

 presumed that his specimens were biserial. They may have belonged to C. areolatus 

 (see p. 465). 



12. Camptoplites retiformis var. tenuispina var.n. Fig. 48 C, D, E. 



Station distribution. Antarctic: Weddell Quadrant, Sts. 195, 363, 371. 

 Geographical distribution. South Sandwich Islands; South Shetland Islands (Discovery). 

 Holotype. St. 195, South Shetland Islands. 



The specimens from the South Shetland and South Sandwich Islands appear to 

 represent a distinct variety, differing from the typical form in the ovicells and in the 



