306 l'K()(KKt)rXGS OF THE ACADEMY OF [1890. 



and it is singular that the hitter author states that the habitat of the 

 .s[)ecies is unknown.' 

 Orbicella ^\<. / 



A well-presei'vc^d, waslied fragment of a subglobose form, \vho.se 

 characters do not seem to fit in with those of any described species. 

 In general appearance it at once recalls 0. annularis, and not im- 

 possibly it may be a variety of that species; but the septa of the 

 coralluni are compound, divaricating or trivaricating, and appear 

 in transverse section 24 in number. They are much finer than in 

 typical 0. annularis, as are also the irregular and multii)le cells in 

 the intercalicular wall. 



P^'ound on the beach of the Isla Verde. 



! Orbicella cavernosa, Esper. 



Several fragments from Sacrificios Island and elsewhere which I 

 doubtfully refer to this species. The intercalicular spaces are large- 

 ly cellular, with the form in part of the letter V, and the species thus 

 approaches 0. radlata, Ellis and Solander. From the latter it is, 

 however, distinguished by the smaller size of the calyces, and by the 

 more compact coralluni. In certain respects, again, the species ap- 

 l)roaches 0. glaucopis, of Dana, from the Fiji Islands.'^ 



This species of coral is largely represented in the wall-structures of 

 Vera Cruz, but a second related species, possibly 0. radiata, occurs 

 associated with it. We failed to obtain any living OrhiceUm in the 

 Vera Cruz waters, and the species are probably most abundant on 

 the outer tjorder of the reef-sea. 

 Maeandrina strigosa, Dana. 



This is one of the two common forms of brain-coral which enter 

 mU) the construction of the reefs. It forms large orbicular or 

 elliptical heads, four or five feet, or more, in diameter, and shows to 

 great advantage in the shallower waters through its brilliant orange 

 coloring. The basal attachment is often limited in area, and 

 " rotten " besides, so that a strong jerk will frequently dislodge the 

 head from its moorings. In this manner we obtained a number of 

 large specimens, the divers using principally their hands alone in 

 forcing. 



1 Histoire Naturelle des Coralliaires, II, p. 474 (Heliastrsea.) 

 - The Mexican form agrees absolutely with a coral from the Post-Pliocene 

 deposits of Sanlo Domingo, contained in the collections of the Academy, and 

 which has been determined by Pourtales to be O. cavernosa. But in this form, as 

 in its more western representative, the intercaliculars spaces are largely cellular. 



