MADREPORARIAN CORALS 329 



The original description is correct for the six corals collected by the ' Terra Nova ', 

 but requires qualifications if the present series is referred to lilliei, the only other course 

 being to describe 4 new species on characters, which are believed to be dependent on 

 growth as governed by environment. 



The thin epitheca is a marked feature, but, as in the smaller forms from St. 160, there 

 may be external erosion or the attachment of sedentary animals, either of which may 

 induce a thickening of the epitheca by the internal deposition of corallum ; these may 

 also inhibit the broadening of the calice. The result of erosion is to show longitudinal 

 striae corresponding to the internal septa. These cross the circular growth-markings, 

 which for the intermediate series from St. 160 suggest 7-9 growth periods. The epithecal 

 growth precedes the septal, so that the septa are never exsert. 



Septa I and II (12), as a regular feature, meet deep down in the calice in a mass of 

 twisted trabeculae. Then there are septa III and IV; the latter are incomplete only in 

 the smaller forms, and there are as many septa of V as the available interseptal gaps 

 allow, the earlier septa showing little thickening. In the smaller forms the edges of the 

 septa are untoothed and the sides almost smooth, but in the two larger from St. 160 they 

 are studded with low spines. 



The size and depth of the trabecular, and hence false, columella depends largely on 

 the shape of the corallite, in tall forms of small diameter being scarcely visible. The two 

 low forms of St. 160 {b) are relatively shallow with 3 and 2 twisted trabecular pillars 

 standing up on the false columella ; these have 4 cycles of septa. 



The specimen from St. 190 is a very clean and rapidly grown form; its septa are thin 

 and tend to be wavy, while their fusion by trabeculae is so deep down as to be almost 

 invisible. These characters are to a lesser degree seen in two similar specimens from 

 St. 181. 



Genus Desmophyllum (Ehr.) Ed. and H. 

 Desmophyllum capense Gardiner. 

 Marine Inv. S. Africa, iii, 96 (1904). 



St. WS 99, 251-225 m., 7 large specimens; St. WS 250, 257-313 m., i, 45 mm. high 

 by 32 mm. along the length of the caHce, only commencing to show the vertical ridges 

 characteristic of the larger forms. 



Being doubtful as to the range of a species which may include Desmophyllum christa- 

 galli Ed. and H.,i D. itigens Moseley^ and the present forms I must retain this species. 



The outer surfaces of the 7 coralla from St. 99 are swollen out into rounded ridges 

 between the chief septa (I, II and III). Between these larger septa, in accordance with 

 the interseptal gaps that these ridges may provide, are found septa of cycles IV, V, VI, 

 VII and occasionally VIII. A specimen (co-type) of the D. capense before me has similar 

 but lower ridges; its calicular opening measures 38 by 25 mm. and has a rather open 



1 Vide Duncan, Trans. Zool. Soc. 1873, p. 321, XLI 10-16 and Marenzeller, ' Valdivia' Exp. p. 267, 

 XV 2 (1904); the resemblance of the present species to the forms figured in 2 and 26 is obvious. 



2 'Challenger' Rep. p. 160 (188 1). 



