3. DOMOPORA. 35 



owing to the superposition of layer upon layer of the confluent 

 disks ; but in one — R. Francquana (I. c. p. 997, pi. 782. figs. 3-8) — 

 this superposition would seem to have taken place only to a very 

 slight extent. In the two living forms I have referred to the same 

 genus there is no superposition at all ; but as the mode of growth 

 is in other respects so exactly in accord with M. d'Orbigny's ex- 

 cellent description, I have not thought it expedient to institute 

 another genus, or even subgenus, merely on that account. 



1. Radiopora simplex, n. sp. (Plate XXXIV. fig. 2.) 



Rays uniscrial, vertical ; mouths of cells and cancelli of the same 

 size ; peristome entire. (Specimen much worn.) 

 Hah. Mazatlan {Dr. P. Carpenter). 



2. Radiopora cristata, n. sp. (Plate XXXIV. fig. 1.) 



Rays bi- to triserial ; cells at inner ends of rays very long, gradu- 

 ally shortening outwards ; erect, connate ; mouth sharply mucronate 

 on one side, sometimes bimucronate ; pores orbicular. 



Hab. John Adams's Bank, South Atlantic (H.M.S. 'Herald;' 

 MacgilUvray) . 



4. DOMOPORA, D'Orb. 



Zoarium massive, cylindrical, simple and mammiform or obtusely 

 lobed, constituted of successive growths one upon the other ; cells 

 disposed in radiating lines on the free rounded extremity of the stem 

 or lobes, or circularly round the margin ; rays uni- or multiserial ; 

 surface everywhere reticulated with hexagonal pits. 



Domopora, D'Orb., 1847, Pal. Franq. p. 986. 

 Defrancia (pars), Pcuss, Hagenow (nee Bronn), Sars. 

 Stellipora (pars), Hagenow. 

 Tubulipora (pars ), Johnst., Fleming. 

 Millepora (pars), Jameson. 

 Coronopora, Gray (1848), Sars, Smitt. 

 CorymDopora, Smitt (nee Michelin). 



1. Domopora truncata, Jameson. (Plate XXXI. fig. 1, 2.) 



Zoarium simple or lobed (proliferous) ; cells disposed in 12-14 

 elevated biserial rays on the rounded extremity of the trunk or 

 lobes. 



Millepora truncata, Jameson, Wern. Mem. i. p. 560 (nee Fabricius, 



nee auct.). 

 Tubulipora truncata, Fleming ; Johnst. B. Zooph. p. 271, pi. xxxiii. 



figs. 8-10; Blainv. 

 Coronopora trimcata, Gray, List B. Pad. p. 140 ; Sars, Reise Lof. 



Finm. p. 145 ; Bmk, Pep. Brit. Assoc. 1859, Tram. Sect. p. 146. 

 Corymbopora fungiformis, Smitt, Overs. 1866, pp. 407 & 490, pi. xi. 



figs. 13 & 14. 



