330 DISCOVERY REPORTS 



centre. Four of the larger specimens above, 58 by 35 mm., 48 by 30 mm., 75 by 45 mm. 

 and 58 by 35 mm., have 15, 18, 20 and 18 ridges; all are much closed in the centres of 

 their calices by the inner edges of the packed and upstanding septa. The ridges extend 

 down nearly to the bases of all four specimens. All are broken off by the trawls 

 above their attachments, providing transverse sections; these show no endothecal 

 trabeculae like dissepiments, except in one specimen, which is decayed in its lower parts, 

 and here they are most irregular but useful in strengthening the corallum. Trabeculae 

 may join together the larger septa in the centre of the corallum, thus producing a certain 

 obliteration of such axial space as exists. 



The coralla would seem to form clusters, but there is no suggestion of other than an 

 adventitious association of polyps. There is little internal thickening of the theca, but 

 the edge zone of the polyp, as far down as it persists, would seem to be depositing 

 corallum on the same and thus filling in the intercostal spaces. The specimens are much 

 overgrown by worm tubes, by hydroids, etc., and the edge-zones of the polyps do not 

 exist outside the theca for more than about 10 mm. 



I have specimens oi DesmophyUum before me identified by Pourtales as Desmophyllum 

 christi-gaUi Ed. and H., Desmophyllum nisei, Desmopliyllmn cailleti both Duch. and Mich., 

 from the West Indies, also Desmophyllum vitreum Alcock ; all of these on the material 

 before me, I regard as good species. The constant difficulty in identification in genera 

 such as this, with a growth to a large size, is a lack of knowledge as to whether any speci- 

 men is adult or immature. Judging by the ways of nature, there must be an immense 

 mortality in the young, few surviving to the adult stage, one perhaps in 1000 or more. 



Genus Caryophyllia Lam. 

 Caryophyllia cyathus (E. and S.). 



Madrepora cyathus Ellis and Solander, Nat. Hist. Zooph. p. 150, xxvni, 7 (1786); Ed. and H., 

 Ann. Set. Nat. ser. 3, ix, 287, iv, i (1848); Lacaze-Duthiers, Arch. Zool. exp. gen., ser. 3, xv, 12-91 

 (1897); Marenzeller, ' VaUivia' Exp. p. 295, XVI 6 (1904); Doderlein, Mit. Zool. Sta. Neapel, xxi, 

 117, VII I, 2 (1913). 



There is much confusion in literature between three of the earlier described, larger 

 species. The aim in growth of clavus is 16 pali, while in cyathus and smithi it is 24, the 

 same number as is sought for in graitdis,^ which is founded on a series of 71 specimens, 

 all markedly cornute and mostly lying unattached upon the bottom. The specimens of 

 smithi that I have examined do not exceed 15 mm. in diameter, whereas cyathus is much 

 larger. C. profunda, also with 24 pali, differs in the great thickness and exsertness of 

 septa I-III and in its columella being more deeply situated and in consequence smaller. 

 It is just conceivable that these three species are environmental variations of cyathus, 

 but details of surface structure do not support this suggestion. 



All the present specimens are attached forms. Each has a relatively broad base, an 

 even column for about two-thirds of its height ending in a spreading out, slightly 



1 'John Muiray' Exp. v, 117, I 2 (1938). 



