78 MADREPORARIA. 



Specimens called " clavaria " mingled with others called furcata are also recorded from 

 Nassau. The former are said to have been the stouter forms, branched to a very limited extent 

 and provided with small crowded cells, but they have the general habit of the species clavaria. 

 Here we find the Author following the suggestion of Pourtales, that the names clavaria and 

 furcata could be used descriptively. As above shown, there is no historical nor morphological 

 justification for such a use of the names. The confusion it led to is described in the Intro- 

 ductory Historical review, p. 3. 



63. Porites Bermuda 1. {F. Bermuda prima.) (PI. IV. fig. 7 ; PI. XII. fig. A.) 



[Bermuda; British Museum.] 



Description. — The corallum is a large, confused tangle of short, thick stems, matted 

 together into an almost soUd mass, upon the shell of an Area. All but the uppermost suiface 

 was dead, and the produce of previous growths. From this surface, stems about to fork, and 

 single branchlets arise, covered by the living layer for varying distances from 2 to as much as 

 6 cm. deep. The forking seems to take place at intervals of about 1 cm., hence the whole is 

 compact and squat, and the short, blunt terminals frequently taper rather suddenly and 

 irregularly. 



The calicles are large, 1 • 75 mm. in diameter, and conspicuously pitted without being deep. 

 The walls are raised as an exquisitely delicate, filamentous zigzag, quite smooth and often 

 incomplete. The septa start also as short, equally delicate processes, each with a minute, 

 frosted or lobate knob at the tip. Below the rim of the wall, and this uppermost tier of septa, 

 the skeletal elements rapidly thicken, and the same details are repeated in stouter and finely 

 echinulate elements. From these thicker, deeper septa, a ring of delicate pali, each tipped 

 with a small lobate knob, rises nearly to the height of the wall. Although the formula of 5 

 with a minute central tubercle can be made out, its real symmetry is not easy to unravel. 



The section is interesting because it shows the trabeculse as tliick, irregular, and flame- 

 like, and ending at the surface in very thin, delicate points and spikes, forming the wall 

 trabeculse and the pali. The surface, in side view, consists of a forest of thin rugged spikes 

 mostly with minute knobs at their tips. 



This coral, of which there is only one specimen, was, according to the custom, labelled 

 Porites clavaria by Briiggemann. Its very squat growth-forms, and the peculiar character 

 of the skeletal elements at the growing surface are sufficient to differentiate it. 



The stock was apparently suffering from some malady. Small, smooth nodules, some- 

 times recalling uprisings of tabular to the surface, as if the polyp had to defend itself against 

 some intruding foe by walling it round and over, occur here and there all over, while patches 

 of 1 cm. square and less, quite killed down, are found on almost every terminal. 



For the sudden thickening of the skeletal elements just below the surface, see P. Florida 

 ^ and 5. 



a. Zool. Dept. 61. 8. 7. 7. 



