A. E. Verrill — New American Actinians. 



497 



The completely developed state of this species is probably 

 unknown. Prof. Mark has figured a free stage, presumably 

 raised from the parasite, with sixteen tentacles, in two un- 

 equal cycles, and with a rudimentary mucous sheath. The 

 latest stages raised by me from the parasite had but eight ten- 

 tacles and did not form a sheath, though it was then con- 

 siderably longer than the young of E. lineata V. having 18 

 tentacles. Hence I do not think it can be the young of the 

 latter, as Prof. Mark suggested. Moreover, its colors are 

 entirely different and the tentacles are much shorter and more 

 obtuse. It is more likely to be related to E. pallida V. than to 

 any of the other known species. It resembles some of the 

 European species that are also parasitic in jelly-fishes, while 

 young. It is very contractile and is protean in form. 



This parasite was first noticed by Mr. A. Agassiz in 1865,. 

 North Amer. Acal., p. 23, but he did not recognize it, at that 

 time, as an actinian. I have a good series of drawings of it 

 made in 1881-1883, showing its generic characters. Figs. 

 2 and 3 are by J. M. Blake, from life. 



Dactylactis viridis, sp. nov. Figures 4, 5, 6. 



A free-swimming cerianthid found in the Gulf Stream. 



Column smooth, very changeable in shape, usually about 

 twice as long as broad, in life ; sometimes pear-shaped with the 

 basal region swollen and rounded at the end ; sometimes top- 

 shaped, with the basal end pointed ; sometimes most swollen in 

 the middle. Usually there are no flutings, when expanded, 

 but in some cases, when the base is swollen, it shows slight 

 invections. The margin is plain and simple, tentaculate ; there 

 appears to be a terminal pore. 



Outer tentacles, in the largest two observed, 18 and 20, in a 

 single circle, only slightly unequal in length and size, long, 

 slender, regularly tapered, usually longer than twice the diam- 



