358 ox THE ANATOMY OF A SUPPOSED NEW SPECIES 



All were preserved by dropping into 90 per cent, alcohol — sometimes with addition of 

 formalin — which seems in most cases to have penetrated rapidl}', so that they are 

 well preserved for histological purposes. 



The genus Coenopsammia was first defined by Milne Edwards and Haime (6), 

 who described nine species and placed the genus in the family Eupsainmidae. The 

 classification of these authors was in the main retained by Martin Duncan (5), who 

 gi'ouped in a somewhat ai'bitrary manner their several families into various alliances, 

 and added the definitions of the numerous new genera described since the publication 

 of the Histoire des Coralliaires (6). 



The genus Coenopsammia is one of the simplest members of the family Eupsam- 

 midae, and the sjiecies here described has no zoosanthellae in its endoderm and must 

 hence feed entirely by means of the food taken in through its stomodoeum. Further- 

 more it produces buds from the basal edge of the polyp as do the most primitive 

 colonial Actiniae, and might therefore reasonably be expected to retain much of the 

 structure of the Hexactinian pol^'ps from which all the Madreporaria seem pi'imitively 

 to have been derived. 



For the so-called mesogloea or jelly I prefer to use the term structureless membrane 

 or basement membrane, as the layer apjjears to me to be of the same nature as basement 

 membranes in general. 



SECTION I. 



General Anatomy of the Skeleton and Specific Description. (PI. XXXIV., Figs. 



1 — 3, and text-figures, I. II.) 



The corallum' is devoid of any epitheca, the whole except the attached base being 

 covered by the polyps. It occurs in its younger stages in the form of a single 

 corallite, which is gradually built up by the polyp, increasing both in diameter and 

 height. At the same time the theca is thickened near the base of the corallite by 

 deposit from the extrathecal portions of the polyp ; and irregularly arranged intrathecal 

 platforms, or pseudotabulae, are formed across the calice. 



Budding takes place near the base of the parent corallite, two, three or more 

 daughter corallites being constantly found of about the same size and age. The buds 

 at first project almost at right angles from the sides of the original corallite, but by 

 a more rapid growth of their outer or distal sides gradually turn upwards, yet always 

 at some slight angle to the parent corallite (Fig. 2). The greatest diameter of one such 

 corallite w^as 7'5 mm., and of its three buds from .3"5 to 5"o mm. The original corallite 

 was 14 mm. high, and the calices of the budded corallites formed a ring about 5 mm. 

 below the margin of its theca. 



' For definition of terms relating to the skeleton see Martin Duncan (5). 



