28 MADRACIS ASPERULA. 



NatweUes, but there are no sufficient grounds for separating them 

 specifically. 



The eolor is variable, sometimes light brown with black or dark 

 brown calicles, or purplish pink of different shades, with or without 

 darker calicles. 



West ofTortugas, in Sfl fathoms.. 



Saint Nicholas Channel, off Babia tie Cadiz, in 120 fathoms. 



Madracis decactis Yerrill (Astrcea decactis Lyman. Proc. Bost. Sue. 

 Nat. Hist, Vol. VI., 1857), Plate VIL, figs. 1. 2, and 3, is found to a 

 depth of 17 fathoms. It is generally thin and incrusting, but also rising 

 in club-like masses. A specimen received from Mr. R. Arango, in 

 Havana, forms thick branches bluntly expanded at the end. 6 cm. 

 high, and 4 cm. in diameter.* Stylophora incrustans Duch. & Mich. 

 1 strongly suspect to be a young Madracis decactis,^ and Reussia lamelr 

 losa Duch. £ Mich., the full-grown form, t 



Stylophora mrahiHs Duch. & Mich, is a Madracis also, with mas- 

 sive caenenchyma. 



The Museum of Comparative Zoology has also received from Mr. 

 Arango, in Havana, specimens of a coral, which agrees with the 

 description of AxoheKa myriaster, M.-Edw. & H. It differs from 

 Madracis mirabiUs chiefly by its striated caenenchyma and larger 

 calicles, which, instead of being prominent, are rather sunk below 

 the surface. 



* The polyp is purplish brown, tentacles tip'ped with white; disk emerald green, mouth yellow. 

 The mural lines separating the polyps are tipped with white. The tentacles are in one circle, five 

 of them large, prominent, and almost spherical when fully expanded, the white tip swelling up in 

 that shape. The other tentacles are in groups of three between the larger ones, the total number 

 being thus twenty, or double the number of the septa. There are thus five primary, five secondary, 

 and ten tertiary tentacles. The disk, when fully expanded, projects in the shape of a cone, with 

 the mouth at the apex. The water is kept in a whirling motion over the mouth by ciliary action. 

 The animal bears handling and taking out of the water very well, expanding again after a few min- 

 utes of rest. 



t Duchassainj et Michelotti, Supplement au Memoire sur les Coralliaires, Piute IX., fig 3, is evi- 

 dently a magnified portion of Stylaster elegans, represented on fig. 4. Fig. 2 may be intended to 

 represent Stylophora incrustatis, the numbers having been misplaced. 



J There is again here (Duchassaing et Michelotti, Memoire sur les Coralliaires des Antilles) a 

 confusion in the numbering of the figures, and in the figures themselves. One of the generic char- 

 acters of Reussia (differing in no way from those of Madracis) consists in having always ten septa. 

 Fig. 9 of Plate IX., purporting to be a magnified portion of Reussia lamello.<a, shows from fourteen 

 to twenty-seven ! Fig. 8 agrees well with the large specimens of Madracis decactis from Havana. 



