258 ZOOPHYTES. 



and the narrower gyri, distinguish it from the labyrinthica. There 

 are twenty to twenty-two equal lamellfe to half an inch ; and in a ver- 

 tical section, obtained by fracture, these thin lamellae form very deli- 

 cate striations of the surface. Obsolescent intermediate lamellee may 

 be distinguished between some of the larger lamellae. 



5. MEANDRINA INTERRUPTA. (Dana.) 



M. convexa et undulata ; discis linearibus sublongis (sive brevissimis, 

 sive longis), scepe lobatis, subgyrosis; gyris 2-2|'" latis, paulum ince- 

 qualibus. Corallum subcellulasum, robustum ; septis solidis, triangu- 

 latis ; fossis fundo porosis : transverse secto, septis irregularibus fere 

 1'" crassis, omnino solidis; lamettis tenuibus, majoribus alternis et con- 

 fertis, minoribus obsokscentibus. 



Surface convex and undulate; linear disks rather long (some very 

 short and others long), often lobed and subgyrose, gyri 2-2| lines 

 broad, somewhat unequal. Corallum firm; fossae porous at bottom : 

 in a transverse section, septa irregular, nearly a line thick, solid ; 

 lamellae quite thin, alternately large and small, crowded, the smaller 

 obsolescent. 



Plate 14, figure 18, transverse section of corallum. 



West Indies. 



The breadth of the gyri is nearly the same as in the strigosa and 

 rustica, but their irregularities and the alternately small lamellae, re- 

 gular, though nearly obsolete, distinguish the species. The septa, 

 moreover, are much stouter than in the strigosa, and in worn speci- 

 mens are triangular ridges, often quite uneven ; the lamellae are much 

 thinner than in the rustica. The larger lamellae, in a section, are even 

 and about eighteen to half an inch ; or counting the obsolescent inter- 

 mediate lamellae there are in all thirty-six to forty in this distance. 

 In this particular the species differs widely from the phrygia. 



6. MEANDRINA RUSTICA. (Dana.) 

 M. hemispherica; discis linearibus viz longis, gyrosis ; gyris 2|-3'" 



