582 DR J. STUART THOMSON ON 



Nephthya thyrsoidea, Verrill. Plate vi. figs. 8, 8a, 8b. 



" Corallum thyrsoid, consisting of a pyramidal head of compound, glomerate clusters 

 of polyp cells, supported by a short, thick pedicel. The short branches arise from all 

 sides of the main trunk and spread abruptly, dividing at once into numerous small 

 rounded lobes, which are densely covered by the crowded polyps ; cells larger than the 

 preceding less thickly covered by the spicula, which are yellowish gray and quite 

 small. Height of the largest specimen, 3 inches, diameter 2, diameter of pedicel "5, 

 length of naked part '75. False Bay, Cape of Good Hope." 



' Taken commonly in small clusters, rarely in large ones, in 20 fathoms, rocks. Oct. 

 1853. Colour, wine-yellow or light brown ; polyps, dark purplish under the tentacles ; 

 the latter palish, nearly white ; stalks with irregular, elevated silvery lines of spicula. 

 Dr Wm. Stimpson.' 



It is to be noted that the last paragraph was not written by Verrill. 



Eunephthya thyrsoides, Verrill. 

 Nephthya thyrsoidea, V. 



"Spicula mostly long, thorny, club-shaped, "600 of a millimetre to TOO long, by '100 

 to '200 thick ; and stouter very thorny clubs, '300 to "500 long, by "125 to '250 broad ; 

 and rough sharp, three-pronged spicula, '275 to '325 long, by '150 to "250 broad. The 

 thorny ends of these spicula project from the surface of the verrucae, especially towards 

 their summits, giving it a very rough appearance. Dr Gray, in the work cited above 

 (Ann. Mag. Nat. Hist., ser. 4, vol. iii. p. 121, Feb. 1869), erroneously places this 

 species as a synonym of Verrilliana thyrsoides, Gray (Ammoihea thyrsoides, Ehr.), 

 from which it differs widely." 



Kukenthal has emended the genus Eunephthya, and places E. thyrsoides, Verr., 

 under " Species incerti generis." He regards it as probable that E. thyrsoides does not 

 belong to the genus Eunephthya but to Capnella. We must, however, bear in mind 

 that E. thyrsoides is one of the two types on which this genus was founded. In 

 Capnella, the walls of the canals are very rich in spicules, a character which is not 

 found in my specimen. In my specimens, it is also noteworthy that the polyps are 

 frequently but not always curved inwards towards the centre of the lobes. It appears 

 to me that too much stress should not be placed on this character as a distinctive 

 feature. 



Studer's admirable definition of the genus Eunephthya, Verrill, is as follows : — 

 " Nephthyidae de forme arborescente ; polyps rigides, non retractiles, en faisceaux a 

 l'extremite des branches, sans spicules de soutien. Ccenenchyme mince; l'epaisseur 

 des branches est surtout formee par les tubes des polypiers. Les sclerites sont des 

 spicules en forme de fuseaux trapus, de massues et de doubles 6toiles." 



Locality, etc. :— P.F. 13,361. Cape Morgan, N.W. £ W. 6| miles. By dredge. 

 Depth, 45 fathoms. Nature of bottom, broken shells. Date, August 13, 1901. 



