125 



Cliiroueplitliiid and Gorgonid-like in Siphonogonjia, is also unworkable, since we 

 have fountl forms, agreeing in armature and spiculation, exhibiting both types. 



The arrangement of the main canals is also a character on which little 

 stress can be laid. Two types may be distinguished in extreme forms, one 

 with thin collapsil)le walls and large irregular canals, the ClilroHcplithyn type, 

 and another with small circular canals and thick hard walls, the SlphoiKxjin-gia 

 type. Linking types exist, however, and apart from these we should not feel 

 justified in separating the two genera on so slender a basis. 



We are therefore inclined to merge them, as Kiikenthal has proposed, 

 retaining the older name Siphonogortjia. 



Siphonogorgia variabilis (Hickson) ( = Chironephthya variabilis, Hickson). 



This species, described by Hickson (1903), is represented by several speci- 

 mens. We submit the following details as a contribution to the study of the 

 variability of this plastic species. 



(A) A slightly damaged specimen, 13 cm. in height and 6-5 cm. in breadth 

 consisting of a main stem, broken near the base, 1'8 cm. long and 12 cm. 

 in diameter, which immediately divides into two main branches. These again 

 give off secondary branches and in exceptional ca§es tertiaries occur. The main 

 stem and branches are almost circular and are covered by a network of small 

 spicules. The smaller branches are wrinkled, due in part to the collapse of the 

 walls supporting the canals. On these smaller branches the spicules are large 

 and arranged longitudinally. The polyps are scattered irregularly over the 

 branchlets and in no case could a spiral arrangement be traced. Each is sup- 

 ported within a definite calyx. 



The spicules are all transparent, warty, straight or bent spindles. 



(rt) Lai'ge spindles on the branchlets and supporting the verruca?, 2"6 mm. x 



03 mm. ; 2'4 mm. x 0"3 mm. ; 22 mm. x 0"15 mm. 

 (/>) Polyp spicules — mostly club-shaped and curved — warty to spiny, 



0(3 mm. X 005 mm. ; 06 mm. x 004 mm. 

 The colour of the colony is white to greyish. 

 Locality : Persian Gulf, 48-49 fathoms. 



(B) Two magnificent specimens measuring 11 cm. x 45 cm. and 11 cm. x 

 5") cm. The first is a complete colony consisting of a short main stem, 15 cm. 

 long and 18 cm. broad at the base, which first gives off a few small branches 

 and then bifurcates into two main upright branches. These again give off 

 smaller branches and only on the latter are polyps to be found. 



The second specimen is incomplete at the base, which is 1 2 cm. in diameter, 

 and is marked by its profuse branching in all directions, thus forming a com- 

 pact colony slightly flattened in one plane. 



