SiMi'.S(nN — A Revision oj Uic Ourjoncilitluc. 343 



bare strips whicli become more indistinct, Imt still visible, towards tlie tip 

 (fig. 7o). These are spirally twisted ; but this is, no doubt, duo to a general 

 torsion of the colony. In each series the polyps appear in rows diverging 

 from the bare tracts ; this gives a very marked spiral arrangement, but this 

 is also due to torsion. Transversely four or live is a common nundjcr in each 

 series. The verrucae are sub-cylindrical and closely adpressed to the stem ; 

 the outer insertion is lower than the inner. They are about 1'5 mm. in 

 height and 0'75 mm. in diameter at the base. When retracted they are sub- 

 conical, and have eight converging lips (fig. 74). 



The canal system is very definite and typical ; the two main longitudinal 

 canals are extremely large. 



The axis is yellow in colour, and markedly calcareous; the surface is 

 apparently smooth ; it tapers only slightly in the portion preserved. 



LomliUj. — Off Table Island, Cocos Group, Andamans, 15-35 fathoms. 



When we take into consideration the fact that the great majority of 

 these forms are fragmentary, and also the slight basis on which the genera 

 Juncella, Scirpearia, and Scirpearella were formerly differentiated, there is 

 small cause for wonder that the various specimens were referred to one or 

 other of these genera on account of differences which we hope to show are 

 not specific, but only different manifestations assumed by extremely plastic 

 organisms. 



We have made a very exhaustive study of the spicules in all the forms of 

 which descriptions have been given; and although these show certain deviations, 

 nevertheless they may be grouped into a number of more or less definite 

 types. 



Fig. 75 gives a very good representation of the different types and 

 deviations therefrom in the case of the spicules in the Indian Museum 

 specimen. Fig. 72 of the spicules of Hickson's Juncella clongata has also 

 been added, and a comparison of these two groups should at once indicate the 

 affinities of these two apparently difierent forms. A similar comparison 

 might be made with regard to the others with a like result. 



If, then, the character of spiculation can be regarded as specific, we sliould 

 be compelled to unite all these extremely divergent forms into one very 

 variable species. This procedure may, at first sight, seem rather drastic, as, 

 it may be argued, the different variations occurred not in each specimen but 

 in different specimens. 



They distinctly show a range of variation wliich cannot be easily com- 

 prehended within an individual colony. 



We are, however, fortunately in the possession of a large colony which 

 has the same characteristic spiculation, and which does actually slmw a range 



R.I. A. PROC, VOL. XXVin., SECT. B. [2 X\ 



