436 DISCOVERY REPORTS 



however, been seen in C. asymmetricus and C. latus var. aspera. I have never seen three 

 avicularia on a single zooecium, as shown in Kluge's pi. xxviii, fig. 5. 



The avicularia are attached to the proximal gymnocyst. One is always near the 

 proximal border of the opesia, the other may be in close proximity to it (see scars in 

 Kluge's pi. xxviii, figs. 3, 4 and 5, and my Figs. 49 D, 52 A, 54 B, C, D), or in a more 

 proximal position (Kluge, pi. xxix, figs. 3 and 4, and my Fig. 44 A). 



The two groups of species of Camptoplites. The species of Camptoplites form 

 two groups; one characterized by the presence of large, erect hyperstomial ovicells 

 (pi. v, figs. 3. 4 and Figs. 48 A-C, 49 A, B, C, 50 A, B, C, 51 C, 52 A, D, 53 A-D, 

 54 B, D) and the absence of secondary branches (short-celled branches, Waters, 1904, 

 p. 21; rameaux secondaires, Calvet, 1909, p. 9; nebenaste, Kluge, 1914, p. 619); and 

 the other characterized by the presence of secondary branches (e.g. pi. vi, figs. 1, 2; 

 pi. vii, figs. 1-4; pi. viii, figs. 1, 3) and by the shallower ovicells, which are tilted back- 

 wards (Fig. 46 A), and may be a mere cap to the zooecium (Figs. 44 B-E, 45 A-F). 

 The first, or C. reticulatus group, comprises C. reticulatus, C. lunatus, C. retiformis, 

 C. latus, C. atlanticus, C. rectilinear is, C. areolatus and C. asymmetricus. The second, or 

 C. bicornis group, comprises C. bicornis, C. lewaldi, C. giganteus, C. angustus and C. 

 tricornis. 1 As far as its characters are known C. abyssicolus also comes into this group. 



In both groups the lateral rootlets generally form connexions from branch to branch, 

 while the axillary ones attach the colony to the substratum, so that where lateral rootlets 

 are common, as in the species of the reticulatus group, the colony has a reticulate struc- 

 ture. In the bicornis group lateral rootlets may be abundant in the older part of the colony, 

 but the branches are usually free distally, except in the specimen of C. bicornis var. 

 quadriavicularis from St. WS 871 which is reticulate, and in some specimens of C. 

 tricornis, which are matted. 



In the species of the reticulatus group the appearance of the ovicell commonly changes 

 with age, the primary radial sculpture being gradually overlaid by various types of 

 reticulation or punctation (e.g. Fig. 48, A, B). It is therefore important, in describing 

 ovicells of this group, to look for colonies in which a series of ovicells at different stages 

 can be examined. It is also important that balsam preparations should be made, if the 

 details of these changes are to be seen clearly. 



The sculpture of the ovicells of the species of the bicornis group does not appear to 

 change with age. In the reduction of the ovicells the species form a graded series from 

 C. angustus (Fig. 46 A) in which they are tilted backwards, but are only a little smaller 

 than those of the reticulatus group, through C. abyssicolus (Kluge, 1914, text-fig. 18), 

 C. tricornis (Kluge, pi. xxix, fig. 6 and text-fig. 12a), C. giganteus (Fig. 45 E, F) and 

 C. lewaldi (Fig. 45 C, D), to the varieties of C. bicornis (Figs. 44 B-E, 45 A, B, and 

 Kluge, text-fig. jc). The ovicells of the varieties of C. bicornis are not only much smaller 

 in total size, but show nothing except their lip in frontal view. Those of typical C. 

 bicornis are unknown. 



Ancestrulae. The Discovery collection comprises a number of young colonies of 

 Camptoplites with ancestrulae. The ancestrulae are all of the same general pattern, being 



1 See Addendum, p. 501. 



