1899.] COBALLIID^ or MADEIKA. 63 



Key to the four haowii species 0/ Pleurocorallium. 



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



secundum (Dana). " Sandwich Isl." ? 

 Var. elatior Ridley. " Japan " ? 

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



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



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



johnsoni (Gray). Madeira. 

 {h) Polype-cells cj'liudrical ; more than 3 forms of spicula. 



maderense J. Y. J. Madeira. 



(2) Polype-cells Termilion tricolor J. Y. J. Madeira. 



Eepeeenoes. 

 Pleurocorallium tricolor. 



1867. GrBAY, J. E. (ffemicorallium johnsoni). " Additional Note 

 on CoralUum johnsoni." P. Z. S. 1867, p. 126, with a 

 woodcut. 



1882. EiDLEY, Stuaet O. " On the Arrangement of the Coral- 

 liid«." P. Z. S. 1882, p. 226. 



Pleurocorallium johnsoni. 



1860. Geay, J. E. (CoralUum). "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. Geay, J. E. (Hemicor allium). " Additional Note on Coral- 

 Uum 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. EiDLEY, Stuaet O. (Pleurocorallium). " On the Arrange- 

 ment of the Coralliidse, 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 Suheria " 

 mentioned on p. 6L From a photograph. 



Plate VI. 

 Pleurocorallium johnsoni, p. 61, about f nat. size. Fi-om a photograph. 



Plate VIT. 



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

 x2. 



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, y>- 60 : a, h, c, spicula of the cortex ; d, d', d", 



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



5. Pleurocoralliu7n johnsoni, p. 61, spicula of cortex and polype-cells: a, 



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

 X 400. 



