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576 DR J. STUART THOMSON ON 



The dimensions of the colony were as follows : — 



Length of colony, ..... 



Length of trunk, ..... 



Diameter of trunk at junction with polyp- bearing part, 



Diameter of trunk at middle, 



Diameter of trunk near base, 



Length of polyp-bearing part (including polyps), 



Diameter of above at middle, 



Diameter of above near apex, 



Diameter of above near base, 



The polyps are grouped in tufts or lobes thickly crowded on the upper portion of 

 the colony. In the specimen described, these lobes numbered about fifty. The lobes 

 are sometimes subdivided into several (2-7) smaller lobes or lobelets, but the line of 

 separation is not very distinct. At the base of the polyp-bearing part, the lobes are 

 simple and undivided. The lobes vary from 5'5 mm. in length and 3*0 mm. in diameter 

 to 8*0 mm. in length and 7*8 mm. in diameter. The size of the polyps varies, some 

 measure 2 mm. in length and 1 mm. in diameter. 



The arrangement of the polyps on the lobes does not appear to be after any definite 

 plan, but when looked at from the surface, they frequently resemble a miniature blackberry. 

 The surfaces of the polyps are extremely well armed with spicules, in the form of three- 

 rayed and foliaceous clubs, which project all over the surface, and are provided with 

 thorny processes. At the apex of the polyp, the spicules are grouped into eight folds. 

 This is, however, observed only when the mouth of the polyp is looked down upon 

 from above. There are no " Stiitzbiindel." The tentacles are not retracted in all cases, 

 but on retraction, they appear to be drawn back or down in a manner similar to that 

 described as taking place in Alcyonium digitatum. The calyx is apparently absent. 



The wall of the stomodseum is thick, and the siphonoglyphe is ciliated, and directed 

 towards the exterior or away from the centre of the colony. The muscles are only 

 slightly developed, and the dorsal and ventral intermesenterial cavities are slightly 

 smaller than the other six, thus producing a tendency towards bilateral symmetry. 

 The mesenterial filaments are well developed. 



The canals of the main trunk have fairly thick walls, and the latter show a number 

 of spicules. These canals are wide, and those in the centre are larger than those in the 

 rind. Their number appears to be about fifty, and they are connected with one another 

 by capillary tubes. The continuations of the polyp cavities must evidently unite with 

 one another in their downward course through the trunk. 



The spicules are very numerous, and give a hard texture to the entire external 

 surface of the colony. They are more especially abundant on the polyp portion, 

 projecting slightly from the surface, and must form a very efficient source of protection. 

 They also appear to be more plentiful towards the apex of the colony. In the trunk, 



