26 



VERRILL ON THE POLYPS OF THE 



tasia, referred here by Gosse, is said to have acontia, but these organs appear to be wanting 

 in the other more typical genera. 



Genus Dysactis Milne-Edwards 



Column often cylindrical, changeable in form, but not capable of involving the tentacles 

 and disk. Tentacles of two kinds : the inner series long and slender ; the outer short, coni- 

 cal, and subequal. 



Dysactis pallida Agassiz, MS. 



Actinia pallida Agassiz, MS. (1849). 



Column sometimes slender and elongated, more frequently short subcylindrical with a 

 narrow base, enlarging above the middle to the margin of the broad disk ; walls longitudi- 

 nally sulcated ; disk broad and flat. Mouth elongated, narrow ; in alcoholic specimens with 

 prominent margins divided into about twelve small lobes on each side, leaving a fold at 

 each angle. Tentacles well developed ; the twelve inner ones often more than an inch long, 

 very slender and flexible ; outer ones numerous, very short, conical ; between these two 

 sets there are some intermediate in size, about half an inch in length. 



Color of the column light brownish yellow, obscurely striated with lighter ; disk similar 

 in color, sometimes with a lighter halo around the mouth ; longest tentacles a lighter tint 

 of the same, usually with white spots on the inner side, and a larger one at the base ; 

 sometimes there are alternate darker spots. 



The largest specimens were 1.25 inches in height; .50 in diameter at the middle; .75 

 across the disk. (Coll. Mus. Comp. Zool.) 



Charleston, S. C. (L. Agassiz). 



One of the drawings belonging to Prof. Agassiz represents an individual with slender 

 filaments, perhaps acontia, protruding from the mouth. I have not been able, however, to 

 demonstrate the existence of these organs from alcoholic specimens. 



Family Ilyanthidje. 



Aetinincs pivotantes Milne-Ed wards, Coralliaires (1857). Ilyanthidve (pars) Gosse, Actino- 

 logia Britannica (1860). 



Column elongated, tapering below to a pointed or rounded base, without a distinct disk. 

 Base continuous with the walls, often capable of inflation and extension so as to serve for 

 locomotion, and also, sometimes, of adhering to foreign bodies. Tentacles usually in lim- 

 ited numbers, well developed. Acontia apparently wanting. 



Genus Ilyanthus Forbes. 



Isachmcea (pars) Ehrenberg, Corall. des roth. Meeres (1834). lluanthos Forbes, British 

 Actiniadse, Ann. and Mag. of Nat. Hist., vol. v. p. 181 (1840); Milne-Edwards. Ilyanthus 

 Johnston, Gosse. 



Column elongated, obconical, tapering below nearly to a point ; surface smooth, destitute 

 of suckers and verrucse. Base very small, scarcely distinct, perforated (in our species) by 

 a central opening. Tentacles marginal, in three or more cycles. 



