Simpson — A Revision of the GorgoneUidw. 279 



We would, Uiercforc, in view of these considerations, put forward the 

 following emended classification, and proceed to define the various genera in 

 terms of such characters as seem to warrant attention. 



Family GORGONELLIDAE.. 



JuNCELLiD Group. 



Division 1. Spicules include cluhs (Juncella). 

 Division 2. Spicules do not include clubs — 



A. Spicules include long warty spindles and small double-clubs 



(Nieella). 



B. Spicules include double-clubs and elongated double-clubs 



(Scirpearia). 



VIII. — Emended Diagnoses of the Family and Geneea. 

 Family GORGONELLIDAE. 



Specimens belonging to this family may be either simple or branched. 

 "Wlien simple, they frequently attain a length of three feet, though colonies 

 of five or six feet long are not uncommon. "Wlien branched, the branching 

 may be (1) very sparse, (2) more frequent and dendriform, or (3) flabellate. 

 The branches are usually long and flagelliform. The coenenchyma is usually 

 thin, arenaceous on the surface, and very granular throughout ; it is densely 

 packed with small spicules, and is separated into an outer non-canal-bearing 

 part and an inner canal-bearing part. 



The canal system consists of two longitudinal series, situated circum- 

 ferentially ; the inner series separates the coenenchyma from the axis, and 

 the outer separates the two parts of the coenenchyma mentioned above. 

 Between these two series, solenia ramify in all directions and unite them. 

 The canals of the outer series are all equal in size ; but in the inner series 

 there is a certain number, definite for the specimens, larger than the others. 

 These are known as the main longitudinal canals. The most frequent number 

 is two, but three and /oi«* also occur. 



The polyps are disposed in a certain number of longitudinal series, which 

 are defiued by and correspond to the number of main longitudinal canals ; 

 these are separated by longitudinal bare tracts, which occupy the region of 

 the main canals. The verrucae vary greatly in shape, not only in different 

 specimens, but in dilferent parts of the same colony. They may project 

 considerably or may be depressed below the surface of the coenenchyma. In 

 each scries there may bo one or more longitudinal rows ; but the number is 



K.I.A. PKOC, VOL. .\XVUI., SECT. B. [2 .P] 



