THE ALCYONARIA OF THE CAPE OF GOOD HOPE AND NATAL. 581 



of the stomodaeal tube, and seemed to indicate the presence of spicules. The muscles 

 are poorly developed. The mesenterial filaments are very large and conspicuous. The 

 siphonoglyphe, which is broad and ciliated, is directed away from the centre of the 

 colony. The dorsal and ventral intermesenterial cavities are smaller than the other 

 six, and the polyp thus has a tendency towards bilateral symmetry. 



The spicules occur in great numbers, and are especially conspicuous on the surfaces 

 of the polyps. They give a hard consistency to the entire colony. The spicules of the 

 polyps are curved spindles, straight spindles, and clubs. The curved spindles measure 

 from 0'272 by 0*0595 to 0*459 by 0*088 mm. The straight spindles measure from 

 0*1615 by 0*0645 to 0*595 by 0*408 mm. The clubs, or spicules between spindles and 

 clubs, measure from 0*136 by 0*0765 to 0*527 by 0*085 mm. (the breadth being 

 measured at the thicker, upper end). 



A rough section of the trunk shows that there is a great aggregation of spicules in 

 the rind, but only a few in the central part. The spicules of the rind of the trunk are 

 curved spindles, straight spindles, and short, broad spindles. Curved spindles are here 

 not numerous, and measure from 0*272 by 0*068 to 0*453 by 0*085 mm. The straight 

 spindles are not so numerous as in the polyps, and measure from 0*1513 by 0*068 to 

 0*357 by 00544 mm. The short, thick spindles are the characteristic spicules of the 

 trunk as contrasted with the polyps. They measure from 0*102 by 0*0714 to 0*204 by 

 0*085 mm. A few clubs are present, measuring approximately 0*221 by 0*0935 mm. 

 (the breadth being measured at the upper end). 



The spicules of the internal ccenenchyma of the trunk are not so numerous as those 

 of the rind. They are curved spindles ; straight spindles of slender form ; short, thick 

 spindles, and irregularly shaped spicules. The curved spindles are not numerous, and 

 measure from 0*255 by 0*085 to 0*425 by 0*085 mm. The straight spindles (also not 

 numerous) measure from 0*153 by 0*068 to 0*323 by 0*085 mm. The short, thick 

 spindles measure from 0*068 by 0*119 to 0*153 by 0*0935 mm. The clubs measure 

 from 0*119 by 0*068 to 02295 by 0*085 mm. 



After a careful comparison of these specimens with the description and figures given 

 by Verrill, I have come to the conclusion that I am here dealing with young forms of 

 Eunephthya thyrsoides, one of the two types on which this genus was founded. As 

 the early literature of this species is rather difficult of access, and for the benefit of 

 naturalists in South Africa, I quote from the original descriptions : — 



Nephthya thyrsoidea, Verrill. 



" Polyps forming thyrsiform branches of closely clustered branchlets, 3 inches high 

 and 2 broad. Colour, wine-yellow or light brown, with a dark purplish tinge below 

 the tentacles ; tentacles nearly white ; spicula forming elevated, transverse lines of 

 silvery white on the stalks. Cape of Good Hope, 20 fathoms, rocks. Dr Wm. 

 Stimpson." 



TRANS. ROY. SOC. EDIN., VOL. XLVII. PART III. (NO. 19). 85 



