MUSEUM OF COMPAEATIVE ZOOLOGY. 113 



ANTIPATHARIA. 



In determining the Antipatharia of this collection, an attempt was 

 made to use the differences in the shape of the polyps, and in the dis- 

 position and form of the spines, to draw characters for a much-needed 

 revision of their classification. It is generally conceded that the 

 division into genera, based mainly on the mode of branching, as estab- 

 lished by Milne-Edwards and Haime, is not satisfactory. I have used in 

 former papers the name Antipathes as sole generic designation, and shall 

 continue to do so for the present, until more material is accumulated. 



In Plate III. will be found figures, drawn with the camera, of the 

 spines of the West Indian species, and of a few others for comparison. 

 It will be seen that there are at least two different types, — the tri- 

 angular compressed, and the more cylindrical. The latter are generally 

 more densely set, even assuming sometimes a brush-like . appearance, 

 as in Antipathes hwnilis. (Plate III. Figs. 18 and 19.) They are also 

 unequal on the two sides of the pinnules, being longer on the side 

 occupied by the polyps, with a few very much longer ones around the 

 latter. The triangular spines are disposed regularly in a quincuncial 

 order around the pinnules, and in a cleaned specimen nothing indicates 

 the place formerly occupied by the polyps. The only exception to a 

 more or less spiral disposition of the spines with regard to the axis I 

 have found in Antipathes {C irrhipathes) Besbonni, where the spines are 

 in regular verticils. (Plate III. Fig. 6.) Duchassaing and Michelotti 

 have figured the same arrangement in Arachnopathes paniculata 

 D. & M. (non Esper), which I have not seen. In Plate III. Fig. 24, 

 the spines of a very large apparently undescribed species from Mau- 

 ritius are figured, showing frequently a secondary point, somewhat like 

 shark's teeth. 



With regard to the polyps, the drawings herewith presented have the 

 disadvantage of having all been made from alcoholic specimens, in 

 various stages of contraction. Still there are differences from one species 

 to another which cannot be ascribed to that cause. There appears to be 

 a connection between the shape of the polyps and the shape and dis- 

 position of the spines. Those species which have triangular spines have 

 polyps with longer tentacles than those with cylindrical spines, with, a 

 greater tendency to become regular in shape, though there are some in 

 which the polyp is very oblong in horizontal outline, as in A. tetrasticha. 



