104 PROCEEDINGS OF THE ACADEMY OF [1889. 



siderable importance inasmuch as it necessitates an alteration in the 

 definition of the family Sagartidse as given by R. Hertwig 1 One of 

 the essentials of the family is that " the principal septa, or septa of 

 the first order, only are perfect and at the same time sterile." The 

 last portion of this statement, though true for the majority of Sag- 

 artidse, fails in the case of the Aiptasise mentioned. It is not possi- 

 ble to separate Aiptasia from the Sagartidse; the members of the 

 genus possess acontia, cinclides, the primary mesenteries alone per- 

 fect, and a mesodermal muscle in some cases, and these must be 

 considered as the chief characteristics of the family. 



As regards the species to which the form under consideration be- 

 longs, the probabilities are that it is identical with A. pallida of our 

 Eastern coast, since in its anatomical peculiarities it agrees very 

 closely with that form. The impossibility however of ascertaining 

 the coloration, and, what is of much more importance, the occurence 

 and arrangement of the cinclides, have prevented a certain identifi- 

 cation and I have preferred to leave the species in doubt. 



Family ANTHEADiE. 



2. Condylactis passiflora. Duch. and Mich. (Plate vi, fig. 3.) 



Several specimens were obtained of a large form, measuring 3.3 

 -2.3 cm. in height and 2.6-3.8 cm. in diameter when preserved, which 

 resembled in coloration, external characters, and for the most part 

 in internal structure also, the West Indian form Condylactis passi- 

 flora. In the alcoholic specimens the column is of a brick-red color 

 wherever the ectoderm has been preserved, and the tentacles are 

 grass-green, this color evidently being due to the enormous number 

 of zooxanthellse contained in the endoderm. Professor Heilprin 

 informs me to the best of his recollection the tentacles in the living 

 specimens were as a rule tipped with crimson. In a separate bottle 

 is a single specimen evidently identical with the others, and accom- 

 panying it is a note stating that the column was red and the tenta- 

 cles brown. This specimen was found freely floating near the sur- 

 face, but had evidently become detached as its base shows that 

 normally it is an attached form. 



The ectoderm having been macerated away, the outer surface of 

 the mesogloea is exposed to view, and is seen to be divided by fine 

 longitudinal and transverse grooves into small quadrangular areas. 

 These grooves are continued over the limbus upon the surface of 



1 Loc. cit. 



