16 



VERRILL ON THE POLYPS OF THE 



longitudinal and oblique muscular fibres ; at some distance from their upper ends there 

 are rather large, circular, peripheric pores. 



This genus corresponds in part to Cereus of Milne-Edwards, but that genus, as established 

 by Oken in 1815, had for its type the Actinia leltis of authors, which belongs to the 

 genus Sagartia of Gosse. The genus Cribrina of Ehrenberg covers very nearly the same 

 ground as Cereus of Oken, and has for its principal character the perforation of the 

 walls, which is essentially a character of the Sagartiadce, and not of this division. 



Bunodes Stella Verrill. 

 Actinia coriacea? Stimpson, Marine Invert, of Grand Menan, p. 7 (1853). 



Plate I. figures 1-8. 



When in full expansion the column is generally cylindrical, or pillar-shaped with the 

 middle portion smallest, enlarging more rapidly towards the disk than the base ; the 

 height is often double the diameter of the column, but sometimes does not exceed it. 

 In contraction it becomes a depressed cone, covered with radiating lines of suckers. 

 The tentacles are large, not very numerous, about equal in length to the diameter of 

 the disk, often somewhat exceeding.it; in ordinary expansion they are largest near the 

 base, tapering gradually to the obtuse tips. The largest specimens observed have sev- 

 enty-two tentacles of which twenty-four belong to the fifth cycle, which is incomplete. 

 Specimens of about an inch in diameter have usually forty-eight tentacles, forming four 

 complete cycles. Those of the first two cycles are somewhat larger than the rest, form- 

 ing the inner row of twelve, which are generally held in an upright position during 

 expansion, while the rest are curved more or less outward and downward and some- 

 times curiously curled and bent in all directions. The column is sulcated with vertical 

 lines corresponding to the radiating partitions within, while the ambulacral spaces, cor- 

 responding to the chambers below each tentacle, are slightly swollen, and have, at inter- 

 vals of about one fourth of an inch, rounded suckers or verrucse, the upper one of each 

 vertical row being more prominent than the rest, and situated at the margin of the 

 disk, just below the base of the tentacle ; lower down the verrucas belonging to the 

 ambulacra of different cycles do not correspond horizontally, so that they appear to be 

 arranged nearly in quincunx. These suckers have the power of adhering firmly to 

 pieces of shells, grains of sand, etc. Specimens when found are generally covered by 

 such foreign substances, which, however, they very soon discard when confined in an 

 aquarium. The disk is flat or somewbat convex at the centre ; mouth usually a little 

 prominent, with four conspicuous folds; it often has the form of a cross, the transverse 

 opening longest ; at each end there is a small, rounded lobe with a larger one on 

 each side projecting inward and often meeting, thus enclosing a crescent or heart-shaped 

 space at each angle ; the sides of the mouth are formed by a broad lobe on each side, 

 which is often again divided into secondary ones. 



The color of the column is generally pale, pellucid olive-green, sometimes flesh-color ; 

 tentacles, disk, and verrucas a lighter tint of the same, each tentacle sometimes having a 

 well-defined ring of opaque white near the middle and, at the base on the inside, a con- 

 spicuous spot of the same, which is broad below and often cordate, diminishing upwards 

 and blending into the general hue, but these spots are absent on those of the first two 

 cycles ; from the mouth six conspicuous flake-white bands radiate to the primary tentacles ; 



