310 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
incomplete. This distinction is especially useful when only specimens for sectioning can be procured, 
such as those from elevated coral reefs. But there are other differences probably more important. 
S. radians. 
S. siderea. 
Upper portion of the septal margins, between 
Subacute. 
calices, flat. 
Calices deformed; occasionally subhexagonal or 
Subhexagonal. 
rounded. 
Corallites, diameters 3 mm. by 2 or 2.5 mm., or 
Five mm. by 4 or 4.6, occasionally only 3 or 3.5 
even smaller. 
mm. in diameter. 
Calicular fossa, septal margins perpendicular to 
Septal margins slope to the bottom of the calic- 
horizontal plane through bottom of calice. 
ular fossa. 
Septa, fourth cycle incomplete. 
Fourth cycle nearly always complete. 
Columella, solid. 
Papillary. 
The characters that first strike one’s eye are the relatively smaller calices of radians, their 
more deformed outlines, and the flatness of the upper portions of the septal margins between calices. 
Besides, radians seems to be more explanate in mode of growth and to form smaller masses. S. siderea 
quite often forms rather large heads. 
From Culebra. 
Genus AGARICIA Lamarck, 1801. ( -f- TJNDARIA -f- MYCEDItTM, Oken, 1815.) 
Agaricia elephantotus (Pallas). PI. xvii, fig. 1. 
1776. Madrepora elephantotus, Pallas, Blench. Zooph., p. 290. 
1786. Madrepora cucullata , Ellis & Solander, Nat. Hist. Zooph., p. 157, pi. xlii (both figures). 
1791. Madrepora cucullata, Esper, Pflanzenth. Fortsetz., Th. I, p. 83, pi. I.xvn (figs, copied from Ellis & Solander). 
1801. Agaricia cucullata , Lamarck, Syst. Anim. s. Vert., p. 373. 
1815. Mycedium elephantotus, Oken, Lehrb. Naturgesch., Zool., Th. I, p. 69. 
1815. Mycedium cacullatum, Oken, op. sup. cit. , p. 69. 
1846. Mycedia cucullata, Dana, Zooph. Wilkes Expl. Exped., p. 339. 
1851. Mycedium elephantotus, Milne-Edwards & Haime, Ann. Sci. Nat., 3ieme ser., Zool., t. xv, p. 131. 
1860. Mycedium elephantotus, Milne-Edwards & Haime, Hist. Nat. Corail., t. in, p. 74. 
Gregory places Mycedia fragilis Dana in the synonymy of this species, but so far as my observations 
go the two are distinct. 
One young specimen in the collection is referred to this species. It is a thin lamina; the greater 
distance across is 38 mm., and the lesser 26 mm. The parent corallite is not situated centrally, but 
near one edge, on the lowest part of the lamina, i. e., it is sunken. The specimen does not agree 
precisely with the characterization given by Milne-Edwards & Haime. In one calice there are ten 
large, exsert, equal septa; in each of three loculi between pairs of these larger septa are three septa, 
one larger septum with a smaller septum on each side; in each of the remaining seven loculi is one 
small septum. The total number of septa is twenty-six. The larger septa are prominent, especially 
around the calicular fossa. This specimen agrees with the figure given by Ellis & Solander. 
From station 6090, off Culebra, Culebritas light-house. Bathymetric occurrence, 16 fathoms. 
Agaricia sp. Pis. xvm, xix. 
This is a unifacial Agaricia, exhibiting features similar to those of Madrepora, undata Ellis & 
Solander, Agaricia agaricites (Linnseus), and Agaricia elephantotus (Pallas). My opinion is that it 
should be referred to A. agaricites and probably placed in var. undata of Ellis & Solander. 
The following is the description of Madrepora undata: 
“Madrepora foliacea explanata concatenata, stellis serialibus, ambulacris intra Stellas elevatis: 
carinis rotundatis crassis. Tab. 40. Corallium latum, planum, elegantissimum, album, subt.us subtilis- 
sime striatum. Stellae oblongse: centra oblonga, subsoluta, elevata. Ambulacra extra Stellas depressa, 
planiuscula, tandem intra seriem stellarum elevata in carinas crassas rotundatas.” 
In the largest specimen the distance between caiicinal centers in a series is usually about 3 mm.; 
the distance from the top of a ridge below a series to the top of a ridge below the next series varies 
from 5 to 9 mm. The septa and septo-costae are usually rather regularly alternately larger and smaller, 
