552 ZOOPHYTES. 



C. Glomerate or lobato-glomerate. 



I. Cells excavate. 



*13. P. astraeoides. *17. P. limosa. 



*14. P. conglomerata. *18. P. favosa. 



*15. P. lobata. *19. P. cribripora. 



*16. P. fragosa. 



II. Cells none. 



*20. P. informis. *22. P. monticulosa. 



*21. P. erosa. 



D. Thin incrusting. 



*23. P. lichen. 25. P. arenacea. 



*24. P. reticulosa. 



A. Ramosse, ramis non plicatis. 

 I. Cettis excavatis. 



1. PORITES MORDAX. (Dana.} 



P. cespitosa, 3^-4" animata ; ramis subsimplicibus et compressiusculis, 

 infra in ktminam scepe coalilis ; ramulis 1^-2" longis, J" crassis, 

 1" latis, apice plano-rotundatis, non clavatis. Corallum robustum, 

 valde asperatum, cellis grandibus (f '"), profundis, et contcis, septo 

 acuto, scabro. 



Cespitose, alive for 3 to 4 inches; branches subsimple and somewhat 

 compressed, below, often coalescing into a plate, branchlets l to 2 

 inches long, J of an inch thick, and ^ to 1 inch broad, piano-rotund 

 at apex, not clavate. Corallum strong and firm, with the surface 

 harsh ; cells large (f of a line), deep, and conical ; septum acute, 

 scabrous. 



Plate 53, fig. 3, corallum, natural size; 3 a, cell, enlarged. 



Sandwich Islands. Exp. Exp. 



Forms rather open clumps, ten inches broad and six to eight high, 

 consisting of stout branches, often united below into thick plates or 

 cavernous masses. The texture is firm, and the surface peculiarly 

 rough and harsh, being pitted with large and deep cells, having sharp 

 septa, often with the angles prominent. There are seven or eight cells 



