56 THE VOYAGE OF H.M.S. CHALLENGER. 



2. Supercytis, d'Orbigny. 



Supercytis, d'Orbigny, Palaeont. Fran^., p. 1060; "Waters, Quart. Journ. Geol. Soc, vol. xL^ 



1884, p. 692. 

 Fasciculipora (pars), d'Orbigny ; Buek, Brit. Mus. Cat., pt. ill p. 37. 



Character. — Zoarium stipitate ; capitulum expanded, flat or cupped, with numerous 

 furcate or trifid fasciculi projecting round the border. Fasciculi compressed, constituted 

 of coalesced, almost completely immersed zooecia of varying lengths, all of which open on 

 the upper flattened side of the fasciculus or at the extremity. Dorsal surface rounded, 

 even, longitudinally striated and minutely punctate. Ocecia (when present) hemi- 

 spherical, at the base of the fasciculi, and usually on the upper surface. 



It is not easy to assign its proper family place to this peculiar type, but on the 

 whole it would perhaps be more at home among the 'Fasciculinse or Frondiporidse, than 

 elsewhere, the main difference between it and the other members of the group consisting 

 in the openings of the zooecia not being altogether terminal but partly on the upper side 

 of the lobes or lateral fasciculi, or more rarely on the central area of the capitulum, 

 which in one of the forms here described, in the perfect and perhaps more or less 

 immature state, is covered with an even, calcareous, minutely punctate lamina, marked 

 out into very regular hexagonal areolae, from some of which, towards the border, may be 

 seen the slightly projecting orifices of zooecia. In the second species the hexagonal areola- 

 tion is apparently wanting, and in this form a few long tubular zooecia project at the base 

 of some of the fasciculate lobes. 



In the British Museum Catalogue I have described and figured, under the name of 

 Fasciculipora digitata, a species, which as pointed out by -Mr. Waters {he. cit., p. 692), is- 

 in all probability identical with M. d'Orbigny 's Supercytis digitata, but in that specimen, 

 which was a good deal worn, the hexagonally areolated, calcareous lamina of the central 

 area is absent, and nothing is seen but the open orifices of what might be taken for the 

 interstitial canceUi characteristic of the Lichenoporidan group. There can, however, I 

 think, be no doubt that they represent the orifices of stunted or undeveloped zocecia, 

 because, firstly, towards the base of the digitiform lateral fasciculi many of the areolae 

 are actually developed into short zooecial tubes ; and secondly, in none can be traced 

 a vestige of the internal ciliary processes which are seen almost universally in true 

 interstitial cancelli. Besides these marginal stunted zooecia, there may be seen in all 

 parts of the central area similar projecting orifices, which are described by Mr. Waters 

 as the ends of centra^ zooecia slightly exserted, and which, as he remarks, give this portion 

 the aspect of a Diastopora, such as Diastopora sarniensis. 



