MADREPORARIAN CORALS 335 



growth ringed in places and some colonies show thin epithecal coverings. The columella 

 varies greatly ; it may be small and situated rather deeply, especially where the edge of 

 the calice is bent in, or may be quite shallow, extending for half the length of the 

 slightly compressed calice where the edge is straight or spreading. Dead calices with 

 budded off polyps on their sides, still alive, may obtain a diameter of 13 mm., but the 

 ordinary large calice is not more than 9 mm. 



Genus Balanophyllia Ed. and H. 

 Balanophyllia cornu (Moseley). 



'Challenger' Rep. p. 192, text-fig. and XII 11-15 (1885). 



St. WS 83, 75 m., 2 attached coralla with broad bases; St. WS 93, 133-130 m., 

 6 coralla all living and attached, largest 15 mm. long diameter of calicular opening; 

 St WS 243, 144-141 m. 3 cornute forms, unattached, varying up to 13 mm. diameter; 

 St. WS 246, 267-208 m., 5 cornute forms, 3 free up to 17 mm.; St. 839, 404-424 m., 

 I bent, free, cornute form of 22 m.; St. WS 871, 336-341 m., 4 forms, 2 free, largest 

 23 mm. 



We have before us 21 coralla of the present collection from 6 stations, 3 from the 

 'John Murray' collection 229 m., and the 3 ' Challenger ' types from Ki Islands, 129 fm. 

 The latter have a dense heavy corallum with well-marked costae from calice to base and 

 the largest, a dead specimen, has distinct trace of an epitheca. All except three of our 

 specimens show an epitheca and some would be described as of the Thecopsammia- 

 facies. It is best marked, thicker and with transverse growth-hnes, in the largest speci- 

 mens, on which it most closely approaches to the calicular margin. There is a less 

 definite edge to the theca in some specimens than in the types due to a spongy arrange- 

 ment of trabeculae. Generally the costae are not well-marked, in no specimen as promi- 

 nent as in the types, but then the present specimens have not the same firm coralla. 



The important, specific character lies in the arrangement of the septa, which Moseley 

 has shown in his text-figure and which we have not found in other large Balanophyllia. 

 There are no prominent exsert septa or groups of septa. Septa I and II are quite separ- 

 able and at a deep level run into the columella. Septa III, IV and V are as shown by 

 Moseley and any variation in any other septa is in correlation with the depth of the 

 upstanding columella in the axial fossa, a matter which every growth-form settles for 

 itself. It is especially deep in the two small type-specimens and is always a more or less 

 upstanding mass of twisted ribbons, its size variable. 



All the polyps of our specimens as preserved were of a deep brown colour. Their 

 surfaces and internal anatomy were irretrievably damaged. Those from St. WS 93 are 

 recorded as having a yellow corona when alive which we think refers to the lighter 

 peristome, rather more marked around the edge of the stomodoeum. Whether the 

 ascription of our very variable set of specimens to B. cornu is correct or not we cannot 

 say, but they draw attention to an arrangement of septa that may form a sub-section of 

 the genus. We have only found it recorded elsewhere in "Doderlein's figs. 81, 82",^ 



1 Mitt. Zool. Sta. Neapel, xxi, IX (19 18). 



