Simpson — A Revision of the Oorgoncllidae. 'i4o 



TIuis wo sec that this specimen exhibits all tlic variation phases which 

 arc represented in the various specimens previously discussed. 



The canal system is typical ; the two large main canals corresponding 

 to the two bare tracts are very pronounced. 



The axis is cylindrical, calcareous, and made up of concentric laminae. 

 It tapers gradually from the base upwards, and is fairly flexible. The 

 coenenchyma is thus of an almost uniform thickness throughout. The 

 surface of the axis is marked by longitudinal striae, the number of which 

 varies in the different parts of the colony. The following are the chief 

 types of spicules (fig. 81), with their measurements, length by breadth, in 

 mm : — 



(«) Small double-clubs with a narrow constriction, and with openly 



wartedends: 0-076 x 0-038; 0-068 x 0-046; 0068 x 0-034. 

 (h) Smaller double-clubs with comparatively few warts on the ends : 



0-065 X 0-034; 0-061 x 003; 0-057 X 0-038. 

 (c) Smaller double-clubs with the ends more densely covered with smaller 



warts: 0-046 X 0-023 ; 0-042 X 0-019; 0-038 x 0-015. 

 {d) Elongated double-clubs with openly warted ends: 0-08 X 0-023; 



0-068 X 0-031. 

 (e) Elongated double-clubs with closely warted ends : 0-072 x 0-03 ; 



0-068 X 0-027; 0-065 X 0-023. 

 (/) Narrower double-clubs, simulating spindles : 0-076 X 0-019 ; 0-072 



X 0-023; 0-065 X 0-019. 

 Locality. — Providence Island, 29 fathoms. 



In the Cape Collection there is a large number of colonies which are 

 extremely diverse in external appearance, but all of which have essentially 

 the same spiculation. It is absolutely impossible to differentiate these 

 from S, furcata; so that I have decided to include them in this species and 

 give a few notes on each specimen, with special reference to the variations. 



In addition to the more mature colonies, there are a few undoubtedly 

 young forms, the largest of which is only 50 cm., and the smallest 8-5 cm. 

 in length. All are of a creamy-white colour, and form a striking annccteut 

 series, showing the various " types " of verrucae which are undoubtedly only 

 different stages in retraction (fig. 82). 



Locality. — Hood Point, N., 5| miles, 42 fathoms. Bottom : sand and 

 shells. 



We shall commence with those forms in which the verrucae are very 

 small, and gradually pass to those in which they are more expanded, and 

 show that a series exists connecting the must extreme types. 



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