POLYPS AND CORALS. 73 



N 



longer than broad ; its texture firm and dense, its surface 

 longitudinally sulcate, with rather wide ridges, which are 

 crossed by deep transverse wrinkles due to contraction, the 

 surface closely lined by fine vertical wrinkles. Edge of 

 disk exceeding the column and a little revolute, the upper 

 surface covered by about forty radiating rows of short 

 unequal tubercles, five or six in each row, the rows being 

 alternately wider and narrower, the wider ones projecting 

 beyond the outer edge more than the narrower ones, and 

 terminating in a three-lobed or triclentate tubercle, the 

 middle lobe being longest ; upon the inner side of this 

 are two small rounded median tubercles, followed by a 

 deeply bilobed tubercle, which is succeeded by three or 

 more, simple, verruciform tubercles, extending to near the 

 mouth. The narrower rays terminate outwardly in a 

 shorter and much smaller tubercle, with a pointed central 

 lobe, the two lateral ones being scarcely developed ; on 

 the inside of this are two small, median, rounded tuber- 

 cles, often slightly bilobed, followed by a more elevated 

 bilobed tubercle, which is succeeded by three or more 

 small, usually simple, rounded tubercles. Mputh in the 

 alcoholic specimen much protruded and everted. Height 

 of the preserved specimen .6 of an inch; diameter of 

 column .4 of an inch. 



Selio Island, Gaspar Straits, February, 1854. L. M. 

 Squires. 



CORYNACTIS Allman, 1836. 



Corynactis (pars') and Melactis Edw. and Haime, Coralliaires, I, 

 pages 258 and 260, 1857. 



Column smooth, versatile in form. Disk much ex- 

 panded, convex or concave, with the mouth depressed or 

 elevated on a cone, according to the state of contraction. 

 Tentacles more or less scattered on the disk, the outer 

 ones largest, with a pedicel and an enlarged or globose 

 tip. Whether more than one of these organs arise from 

 the same chamber, I am, at present, unable to determine, 

 but this seems probable from the figures. 



The following species, and also O. viridis of Europe, 



COMMUNICATIONS OF ESSEX INSTITUTE, VOL. VI. 10 AUGUST, 1869. 



