8 



VERRILL ON THE POLYPS OF THE 



An examination of numerous specimens of this species in the Museum of Compara- 

 tive Zoology has shown me, that, while it is perfectly distinct from the European species 

 with which it was formerly confounded, and equally so from L. purpurea M.-Edw. of southern 

 Florida, several nominal species have been founded on mere variations in its form and 

 color, their inconstancy being readily seen when a large number of specimens are at hand. 



Leptogorgia tenuis Veekill. 



Branches unequally and distantly dichotomous, arranged somewhat in a plane ; termi- 

 nal branchlets very long and slender ; round and smooth. Cells numerous, small, scattered, 

 oblong, with the borders flat or slightly prominent. Median grooves scarcely apparent 

 even on the larger branches. Cells on the smaller branches arranged somewhat in two 

 opposite bands, but not very distinctly so. Axis towards the base black, in the smaller 

 branches very slender, yellow, and translucent, even at a distance of eight or ten inches 

 from the extremities. Colors, yellowish brown and purple. 



Long Island Sound (Smithsonian Institution). 



Of this interesting species there are numerous specimens in the collection of the Smith- 

 sonian Institution, attached to rocks, and labelled " Bay of New York." It is closely allied 

 to L. virgulata of S. Carolina, but after comparing it with several hundred specimens of the 

 latter in the Museum of Comparative Zoology, I have become convinced that they are dis- 

 tinct. In the present species the branches are more slender and elongated and less numer- 

 ous than in L. virgulata; the cells are smaller and less frequently ju'ominent ; the median 

 grooves are less distinct, and the axis is more attenuated and diaphanous. The color, 

 though probably variable, is different in all the specimens that I have seen, being generally 

 dull yellowish brown or purplish, instead of pure yellow, orange, or bright purple. 



Family PlexauriDjE Gray (emended). 



Gorgonincv (pars) Ehrenberg, Dana. Primnoacece (pars) Milne-Edwards. Plcxauridw and 

 Murieidce Gray, Ann. and Mag. of Nat. Hist., Dec. 1859, p. 442. 



Corallum branching, dichotomous or arborescent, with a horn-like axis, often calcareous 

 and stony at the base. Ccenenchyina well developed, traversed by a series of equally 

 developed longitudinal ducts, arranged in a regular circle around the axis. Cells arranged 

 equally on all sides of the branches, leaving no naked lateral spaces. 



In this family I have united Muricea with Plexaura and Eunicea, the only important differ- 

 ence consisting in the spiculose cells of the former ; but this seems due rather to the thin- 

 ness of the external membrane covering them in life than to any peculiarity of the tissue 

 itself, for in Eunicea the spicula are as well developed and similarly arranged, though cov- 

 ered by a thicker superficial membrane. 



Genus Muricea Lamouroux. 



Gorgonia (pars) Linn., Pallas, Lamarck, and others. Mvricea Lamouroux, Exposition 

 Methodique (1821). 



Axis horn-like in the branches, often stony and very solid at the base. Cells prominent, 



