THE ALC YON ARIA OF PORTO RICO. 
269 
by the ordinary collector or student. While under each family the recognized genera 
are named, only those coming within the range of West Indian or West Atlantic 
coast waters are included in the generic synopses. 
The following authors have also been consulted in the preparation of the report : 
Dana, James D., Kept. U. S. Exp. Exped., Phil., 1846. 
Hickson, S. J., Revision of Alqjonaria stolonifera , Trans. Zool. London, vol. xm; Rept. on Classification, 
Abstr. Jour. Roy. Soc., 1896; Structure and Relations of Tubipora, Quar. Jour. Mic. Sci. 1883, etc. 
Kent, W. S., New Genera Alcyonaria, etc., Quar. Journ. Mic. Sci., vol. x. 
Koch, G. von, Gorgoniden des Golfes Neapel, 1887; Alcyon. Golfes Neapel, Mitt. Zool. Station Neapel, 
vol. IX. 
Lamouroux, J. F. V., Hist, des Polypiers Coral. Flexib., 1816. 
May, Walther, Systematik u. Chorologie der Alcyonaceen, Jenaisch. Zeitsch. Naturwiss., Mar., 1899. 
Nutting, C. C., Anatomy of Gorgonacea, Bull. Laboratories of Nat, Hist, State Univ. Iowa, 1889. 
Pourtales, L. F., Contributions to Fauna of Gulf Stream, Bull. Mus. Comp. Zool., vol. i; ibid., Report 
on Corals and Antipatharia, etc., Bull. Mus. Comp. Zool., vol. vi, No. 4. 
Riiiley, Stuart 0., Reports on New Species from Ceylon, etc., Ann. and Mag. Nat. Hist., ser. 5, vols., 
ix and xi. 
Valenciennes, A., Extrait d’une monographic de la famille des Gorgonides de la classe des Polypes; 
Comp. Rend., 1855. 
Verrill, A. E., various papers, accessible in Bulletin of Museum of Comparative Zoology; Proc. Boston 
Soc. Nat. Hist. ; Proc. Essex Inst, ; Am. Journal of Science, New Haven; Proc. Conn. Acad. Sci., etc. 
ALCYONARIA. 
Polyps and polyp colonies having eight pinnate tentacles and eight mesenteric folds. 
Order 1. ALOYONAOEA Verrill, 
Polyps single or in colonies; when the latter they are united by endodermic nutritive canals; are 
without axial skeleton. 
I. Haimeid,®. Polyps single, with or without spicules. 
II. Cornularidjs. Polyps not united in bundles at the base to a stem or foot, but have cuticle-like 
or stolon-like expansions or are branched and bear lateral buds. 
III. Tubiporidve. Colonies formed of parallel tubular polyps and united by horizontal platforms 
containing endodermal canals. Colonies form calcified stocks of numerous calcareous 
tubes arising from the coalescence of spicules of the mesoderm. Anterior portion of polyps 
is retractile. 
IV. Xenid.e. Colony consists of masses of long cylindrical polyps bearing terminal crowns of 
nonretractile tentacles. Polyps united in their lower portion by a canal system ramifying 
in a connecting coenenchyma, which contains a few calcareous spicules. 
V. Organidac. Elongated polyps united together so as to form a short upright stem. Polyps 
retractile. Spicules present in both polyp and tentacles. 
VI. Alcyoniile. Polyp stalk fleshy, sometimes simple, sometimes irregularly branched. Basal 
portion generally without polyps. Polyp tubes, contained in the thick coenenchyma, are 
united by endodermal canals, from which buds are formed. Isolated spicules are found in 
the coenenchyma. 
VII. Nephthyida:. Upright branched polyp colonies, consisting of a sterile trunk and branches rami- 
fying in a most varied manner and bearing terminal polyps. Polyps do not exhibit separate 
calycine and tentacular regions, and the latter does not invaginate. Tentacles fold over 
oral disk when at rest. Buds arise from small endodermal canals between the polyps. 
VIII. Helioporid.e. Compact corallum formed of a fibro-crystalline calcareous mass. This is formed 
from a coenenchyma made up of numerous tubes and from calyces with an irregular num- 
ber of septa-like parietal ridges. Calyces and tubes of coenenchyma are closed below by 
a series of transverse floors. Polyps completely retractile, and tentacles are invaginated. 
Delicate canals furnish communication between individual tubes and calyces. 
