336 J. E. Duerden — Jamaican Actiniaria : Part I. — Zoantheo?. 



non-pedunculate, practically of the same diameter throughout, but often with 

 slightly expanded portions at the base. In extension the margin of the column 

 is crenate, the elevations alternating with the outer row of tentacles ; on partial 

 retraction, the capitular fossa is well seen. Both inner and outer capitula bear 

 fine ridges and grooves. In complete retraction, numerous minute capitular 

 striae can be seen only on the outer capitulum. Tentacles about 60, arranged 

 in two cycles ; one specimen had 32 in each row. Disc not much depressed, 

 walls thin ; the mesenterial lines can be seen through them ; mouth slit-like, the 

 oesophageal groove not distinguishable ; oesophageal walls thin, showing the mesen- 

 terial lines ; in some examples, the wall is thrown into ridges and furrows. 

 Coenenchyme little developed, appears only as a flattened expansion from one 

 side of a polyp and connected with one or more other polyps near ; in other 

 cases, the connecting strand becomes constricted and stolon-like. Isolated 

 polyps devoid of any coenenchyme are met with, even when closely associated. 



The polyps and coenenchyme adhere firmly to the rocks or stones. New 

 individuals arise by budding from the slightly expanded base of other polyps, 

 and afterwards become more separated, the connecting tissue getting thinner and 

 thinner until the polyps may become entirely isolated. 



Colour. — Column in its lower part, esjDecially when embedded in foreign 

 matter, sand-coloured, becoming a dark blue or slate colour above. The 

 margin has irregularly disposed, silvery white, triangular, narrow, radiating 

 patches, often incomplete and variable in length ; the toothed elevations are 

 nearly opaque white. These white markings, which appear constant for the 

 species, are best seen on partial contraction, at which time the inner capitulum 

 appears as a distinct whitish, toothed, circular annulus. Colours of the tentacles 

 and disc are variable. In a colony from Lime Cay both were a bright orange 

 brown, and the peristome a bright green ; in another large colony from Maiden 

 Cay the tentacles were green on their inner aspect and dark brown on the 

 outer, the disc a dark brown with bright green peristome ; specimens at 

 Rackum Cay showed a bright blue disc with green lips, and the tentacles a 

 bright green. 



Dimensions. — The height differs considerably, dependent upon the position 

 of the polyps in a colon}^ ; it may vary from 2*7 cm. to 0*4 cm. ; the 

 diameter is about 0*6 cm., and is generally constant throughout the column, 

 and independent of the length. The measurements are taken from specimens 

 preserved in formalin, with but little contraction. 



Locality. — Jamaica : Found in considerable abundance, growing on stones 

 and coral rock, in shallow water, around the various Cays outside Kingston 

 Harbour. The polyps are often partially embedded in sand and shore delbris. 



Range. — St. Thomas, Guadaloupe (Lesueur; Duchassaing and Michelotti). 



