1899.] coBALiiiiD.^ or madeira. 63 



Key to the four Tcnown species of Pleurocorallium. 



I. Axis partly red, partly white, cortex scarlet. 



secundum (Dana). " Sandwich Isl." ? 

 Var. elcdior Ridley. " Japan " ? 

 II. Axis wholly white, cortex yellow or cream-colour. 



(1) Polype-cells yellow or cream-colour. 



(«) Polype-cells subhemispherical ; only 3 forms of spicula. 



joknsoni (Gray). Madeira. 

 (Jb) Polype-cells cylindrical ; more than 3 forms of spicula. 



maderensc J. Y. J. Madeira. 



(2) Polype-cells vermiHon tricolor J. Y. 3. Madeira. 



Eefeeences, 

 Pleurocorallium tricolor. 



1867. Geat, J. E. (Remicorallium johnsoni). " Additional Note 

 on Corullium joJmsoni." P. Z. S. 1867, p. 126, with a 

 woodcut. 



1882. EiDLET, Stuaet O. " On the Arrangement o£ the Coral- 

 liidffi." P. Z. S. 1882, p. 226. 



Pleurocorallium johnsoni. 



1860. Geax, J. E. (Corallium). "Notices of some new Corals 

 from Madeira." P. Z. S. 1860, p. 394, Eadiata, pi. xviii. 

 Ann & Mag. Nat. Hist. ser. 6, vol. iii. p. 31 1. 



1867. Gbat, J. E. (Bemicor allium). " Additional Note on Coral- 

 lium johnsoni." P. Z. S. 1867, p. 126. 



1870. Geay, J. E. {Hemicor allium). Catalogue of Lithophytes or 

 Stony Corals in the British Museum, p. 24. 



1882. EiDLET, Sttjaet O. {Pleurocorallium). " On the Arrange- 

 ment of the Goralliidfe, with Descriptions of new or rare 

 Species." P. Z. S. 1882, p. 221, pi. ix. 



EXPLANATION OF THE PLATES. 



Plate V. 



Pleurocorallium maderense, p. 60, about | nat. size. — The object projecting at 

 the top of the fig. is the parasitic Alcyonarian, "probably a Suberia" 

 mentioned on p. 61. From a photograph. 



Plate VI. 



Fleurocorallium johnsoni, p. 61, about | nat. size. From a photograph. 



Plate VII. 



Fig. 1. Pleurocorallium maderense, p. 60, terminal branchlets with polype-cells. 

 X 2. 



2. Pleurocorallium johnsoni, p. 61, a terminal branch with polype-cells. X 2. 



3. Pleurocorallium tricolor, p. .58: a, b, c, spicula of the cortex; d, d', d", 



spicula from the polype-cells. X 400. 



4. Pleurocorallium maderense, p. 60 : a, h, c, spicula of the cortex ; d, d', d" , 



e, spicula from the polype-cells. X 400. 



5. Pleurocoralliuhi johnsoni, p. 61, spicula of cortex and polype-cells: a, 



spicule no. 3 ; hb, spicule no. 1 ; c, spicule no. 2, described on p. 62. 

 X400. 



