1873.] DR. E. t,. MOSS ON A VIRGULARIAN ACTINOZOON. 731 



The specimen from which the following notes are made has indeed 

 already suffered considerable post-mortem disintegration ; its more 

 delicate portions do not admit of the handling necessary for dissec- 

 tion under the microscope. Sufficient, however, remains to enable 

 me to speak definitely as to its position in the animal kingdom, 

 though the absence of means of reference in this colony makes com- 

 plete accuracy unattainable. 



The creature belongs to the Virgularian section of the family 

 Pennatulidse, but differs from those of its genus that I know of in 

 that the lateral ridge-like processes bearing the polypes exist only 

 on one side of the central axis ; in short, to borrow a term from its 

 fossil relatives the Graptolites, it is " monoprionian." 



In this example the pale rosy chocolate tint, so common in its class, 

 is still preserved ; the entire actinosoma (Plate LXI. fig. 1) measures 8 

 feet 6 inches in length. The lower or proximal foot-length (A) is the 

 thickest part ; its diameter is a little over 1 inch ; it is cylindrical ; its 

 end tapers rapidly to a soft cone perforated by a pore (fig. 2) ; and it is 

 grooved externally by twenty-four longitudinal wrinkles. This lower 

 foot-length consists of two cylinders of cartilaginous consistence, the 

 inner, more transparent and firmer, closely enclosing the central hard 

 rod or coral, the outer investing the former and attached to it only by 

 four thin longitudinal septa (fig. 3), passing through the entire thick- 

 ness of the inner cylinder, hut very slightly attached to the central 

 rod. The space included between the two concentric cylinders is 

 thus divided into four equal chambers, ending below at the apex, and 

 above gradually narrowed by the widening of the partitions till they 

 finally disappear about 18 inches from the proximal extremity. A 

 section of this part presents the wheel-like appearance shown in fig. 3. 



Externally a line of minute pores marks the position of each sep- 

 tum ; but I could not trace any connexion between them and the 

 quadrate chambers. 



The second foot-length of the actinosoma is much more slender 

 (fig. 1, B) ; the sarcode closely invests the central axis and presents a 

 twisted appearance. The four lines of pores are still visible exter- 

 nally ; but the space between the layers of soft tissue is greatly re- 

 duced, and at the distal end of this length terminates altogether. 

 At this part the two lines of pores on one half of the organism change 

 their character ; the openings, instead of being very minute and iso- 

 lated, become larger, and a little further on begin to occur in rows 

 of twos and threes. The fleshy parts here project more from the 

 central axis on this side than on the other. At the end of another 

 foot-length the pores have changed into little rows of pits on either 

 side of a ridge of soft tissue, each pit filled with its polype ; and from 

 this part upwards the polype-bearing part of the ccenosarc (fig. 1, C) 

 extends to a gracefully tapering extremity, but presents an unchanged 

 plan of structure throughout. Taking a central part for example 

 (fig. 4), we find the hard round axis of very much the same diameter 

 as below, though above it tapers with the rest of the tissues till it 

 ends in a fine point. It is very thinly covered by the two fleshy 

 layers for about two thirds of its circumference (section, fig. 5); 



