THE ALC YON ARIA OF PORTO RIOO. 
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IX. Plexauridte. Colony usually branched and upright; the axis horny or horny and calcareous, 
especially at the base; ccenenchyma thick; polyps scattered over entire surface; cups 
project little or not at all, appearing in many cases as pores in the coenenchyma; 
spicules large and of various form; cortical mostly club-like, spindles beneath. 
X. GergoniDjE. Colony upright and branched, usually in one plane; axis horny, rarely calcareous; 
polyps arise on stem and twigs in bilateral manner. 
XI . Gorgonellidje. Coenenchyma thin and smooth on surface; spicules warty double stars and 
clubs; polyps on wart-like verrucse, usually arranged biradially; axis lamellar and cal- 
careous; branches and twigs frequently flattened. 
Family 1. BRIAREID/E. 
Eleven genera belonging to this family have been described by various authors, of which four are 
found in this section: 
1. Leucoella Gray. 
2. Solenocaulon Gray. 
3. Semperina Kolliker. 
4. Suberia Studer. 
5. Anthothela Verrill. 
6. Parogorgia Milne-Ed wards. 
7. Briareum Blainville. 
8. Titanideum Agassiz. 
9. Spongioderma Kolliker. 1 
10. Icilogorgia Ridley. 
11. Solanderia Kolliker. 
5. Anthothela. Coral either incrusting or irregularly branched. Branched forms with a distinct 
spiculose axis, composed of fusiform spicula. Callicles prominent; can not be retracted 
within coenenchyma; eight-lobed at summit. 
7. Briareum. Axis not well defined, penetrated by nourishing canals. Colony forms irregularly 
lobed upright masses. Polyps without calyces, completely retractile within coenenchyma, 
disposed regularly on stem. 
8. Titanidium. Stem less porous than in Briareum, spongy, and contains many characteristic spicules. 
Polyps scattered and not very prominent. 
10. Icilogorgia. Stem brittle, formed of spicules packed closely together. The medullary portion is 
surrounded by a series of longitudinal canals. Colony upright, branched, with both stem 
and branches compressed. Polyps arise within a groove along the sharp edge of the 
branches, and are completely retractile. 
11. Solanderia. Colony arborescent. Axis composed of a mass of closely packed unfused spicules 
containing no nourishing canals, but bounded by a layer of rather indefinite, nourishing 
canals. 
Family II. SCLEROGORGID 2 E. 
1. Suberogorgia Gray. 2. Keroides Wright & Studer. 
1. Suberogorgia. Colony upright, branched, with branches sometimes anastomosing. Axis formed 
of numerous closely intercalated spicules with dense horny sheaths. Polyps with slightly 
protruding calyces, disposed on either side of the flattened stems and branches. Coenen- 
chyma thick, with longitudinal furrows on the surface of areas free from polyps. Spicules 
are warty spindles, and in one species birotate. 
2. Keroides. Colony upright, branched in one plane. Axis similar in structure to that of Subero- 
gorgia , and retains its form after decalcification. The polyps form wart-like verrucre, 
disposed mainly on the two sides of flattened branches, leaving a free interspace. Spicules 
are broad spindles and polygonal, often triangular disks. 
Family III. MEUT0DID£. 
1. Melitodes Verrill. 4. Psilacabaria Ridley. 6. Clathraria Gray. 
2. Mopsella Gray-Ridley. 5. Wrightella Gray. 7. Parisis Verrill. 
3. Acabaria Gray. 
No genera of this family seem to have been found in West Indian waters. 
1 Of the separateness of genera 9 and it there is some doubt. 
2d— F. 0. B. 1900 — IS 
