500 ZOOPHYTES. 



b. M. glomeratco aut incrustantes, nunquam benc foliaceae aut ramosae, (serpulas inter- 

 dum tegentes, itaquc subramosse.) 



13. MANOPORA EFFUSA. (Dana.) 



M. explanation incrustans, margine breviter libera; scepe serpulas ascen- 

 dentes tegens, itaque ramosa, ramis tortuosis cylindricis, " crassis. 

 Corallum papilloso-asperum, spinulis -1'" longis, interdum compres- 

 sis et breviter confluentibus, ceUis '" latis, 12-radiatis. 



Explanately incrusting, margin free for a short distance ; often cover- 

 ing growing serpulas, and thus become ramose, with the branches 

 tortuous, cylindrical, of an inch thick. Corallum papilloso- 

 asperate, spinules to 1 line long, some compressed, and for very 

 short distances confluent ; cells of a line broad ; 12-rayed. 



Plate 46, fig. 4, corallum, natural size ; 4 a, view of surface, ditto. 



Tahiti, Society Islands. Exp. Exp. 



The corallum often consists of a series of plates partially united to- 

 gether. The branches formed by incrustation are sometimes six 

 inches long and of nearly uniform size. The margin of the spread- 

 ing plate was free for two or three inches from the edges, thin 

 and turned up; and the surface below was alive for a fourth of 

 an inch, though without cells. The cells above are from a line to a 

 line and a half apart, and in some parts, the confluent spinules form 

 an imperfect septa between two or three cells, or partially encircle 

 them. The corallum is very porous, except the under surface, which, 

 as the animals desert it, is rendered quite compact. 



The Ezplanaria cristata of Peron and Lesueur, may belong near here, though a dif- 

 ferent species. The concise description of it given, is as follows : " Partly incrusting, and 

 in part plicato-cristate, rising into crests more or less plicate ; cells very minute, not pro- 

 minent; under surface finely arenaceous, but not striate." Lamarck, ii. 400, sp. 6. 



14. MANOPORA STILOSA. (H. $ Ehrenberg.} Dana. 



M. effusa, glomerata, incrustans, rubella, super -fide tuberculoso-conveza ; 

 polypis kete violaceis, aut rubescentibus, disco lineis 12 albis violaceis 



