196 ZOOPHYTES. 



This beautiful species grows in hemispherical clumps, often a foot 

 in diameter. The slender laciniations of the upper margin of the 

 crest-like folia are half or three-quarters of an inch long, and are 

 extremely fragile. Owing to their brittleness, specimens in collec- 

 tions are often deprived of them. The large cells are mostly one to 

 two inches in breadth. 



According to Quoy and Gaymard, the animal has a grayish-green 

 glaucous disk, without tentacles. The latter character is probably 

 incorrect, as these organs were distinctly seen in the following species. 

 They are very short, and often will not expand, except after being left 

 quiet for a considerable time in pure ocean water. 



Perinagna et valde elegans concha fungi- , Lamouroux, Exp. Meth. 53, tab. 44. 



formis, &c., Seba, iii. tab. 89, fig. 10. Tridacophyllia lactuca, Blainville, Man. 



Madrepora lactuca, Pallas, Zooph. 289. 362, pi. 56, fig. 1 a much reduced 



, Ellis and Solander, tab. 44. figure, with the crests broken. 



, Esper, Fortsetz, i. 7, tab. 33 A., a , Quoy and Gaymard, Voy. de 1'Ast. 



copy of Seba's figure ; 33 B. from Ellis. iv. 221, pi. 18, fig. 1 not good, unless 

 Pectinia lactuca, Oken's Zool. i. 68. it belong to a different species with sub- 

 Pavonia lactuca, Lamarck, ii. 377, No. 3. entire and not deeply laciniate crests. 

 , Schweig. Handb. 414. Manicina lactuca, Ehrenb., G. Ixiii. sp. 12. 



Tridacophyllia manicina. The Madrepora lactuca of Ellis (Ellis and Solan- 

 der, tab. 44, and Esper, tab. 33, B.), of which the West Indies is given as the locality, 

 appears to be another species with the foliated crests scarcely laciniate. A worn speci- 

 men resembling it, belongs to the collections of the Boston Natural History Society. It 

 is nine inches in diameter, and has a massive base four to five inches thick, with the 

 foliate septa one to two inches high. When these ridges are worn away, the specimen 

 resembles a light coarsely cellular Manicina or meandrine Mussa, with the cells one 

 half to three-fourths of an inch wide. The Manicina lactuca of Ehrenberg (Gen. Ixiii. 

 sp. 12), though made identical with the Tridacophyllia lactuca of authors, appears to be 

 Ellis's species. 



2. TRIDACOPHYLLIA P^EONIA. (Dana.} 



T. convexa, disco brunneo, 1" lato, rugato, extra tentaculos griseo- 

 virescente ; tentaculis minimis. Corallum septis foliaceis vaKdioribus, 

 minoribusque, fere 2" altis ; cellis scepius 1" latis, rarissime oririmis 

 later alibus; lamellis numerosis, superne non obsoletis, paulum granu- 

 losis ; super -fide inferiore striatd, striis densioribus. 



Convex ; disk brown, to 1 inch broad, rugate, exterior to the tenta- 



