732 DR. E. L. MOSS ON A VIRGULARIAN ACTINOZOON. [Nov. 18, 



but its remaining third supports the edge of an expansion of the 

 softer tissues in much the same way in which the ridge on the back 

 of a scythe supports the blade. The two sides of this expansion bear 

 lines of polypes rank over rank in echelon formation, caused by the 

 rows sloping diagonally upwards and outwards, an arrangement which 

 would prevent the mouths of the polypes being turned away from a 

 current of water which, if the lower end of the actinosoma were em- 

 bedded in sand, would bend its slender stem as the wind bends grass. 



The polypes themselves are not independent of their cells, are 

 flask-shaped (fig. 6), and about \ inch in length ; their eight-rayed 

 summits retractable into the little transparent collars of ectoderm sur- 

 rounding them, and their bases filled with salmon-coloured ova lying 

 in pits on either side of the gristly blade of endoderm which supports 

 the polypes and the tissues that form them, and is itself supported 

 at its edge by the central rod. The polypes are striped by eight 

 lines of mesentery, clearly defined by dark crimson (probably sper- 

 matic) granules lying between them. On making a transverse section 

 (fig. 5) the relation of the two fleshy coats to each other and to the 

 coral becomes more evident. Two small longitudinal canals lie on 

 either side of the median cartilaginous blade close to where it divides 

 to enclose the axis. The whole of this cartilaginous tissue is tra- 

 versed by minute whitish canaliculi, but is otherwise transparent and 

 untinted by the reddish colour which pervades the outer sarcode. 

 The latter layer contains no spicules ; but its surface is dotted at ir- 

 regular intervals by oval white cells (articulating organs, I presume, 

 though the softened state of the specimen prevents me making cer- 

 tain of their character). 



Both the minute structure and general habits of this Sea-pen must 

 remain conjectural till an observer can study it alive in its native sea. 

 The fishermen say it swims free, and is so caught in their nets ; but 

 though the absence of any fractured actinorhiza makes it probable 

 that it can do so, yet the twists in the narrow part of the organism, 

 just before the polype-bearing portion begins, and the arrangement 

 by which the root portion might, by the dilatation of its chambers, 

 act as an anchor, seem to indicate a fixed habit, which is made fur- 

 ther probable by the fact that the creatures are always captured in 

 certain places, and have never been met with in the open sea. 



The common but very improbable statement that this actinozoon 

 is confined to Burrard's Inlet is altogether premature, as the infra- 

 tidal region of this coast is almost altogether zoologically unknown. 



DESCRIPTION OF PLATE LXI. 



Fig. 1. Complete actinosoma, much reduced: A, root; B, neck; C, polype- 

 bearing portions. 



2. Proximal extremity, natural size. 



3. Section 6 inches from proximal extremity, natural size. 



4. Central portion from polype-bearing part of actinosoma, natural size. 



5. Section of central polype-bearing portion, natural size. 



6. Polype, magnified 3 diameters. 



