1020 



MISS R. HARRISON AND PROF. S. J. HICKSON ON 



expecting to find them it would be very easy to overlook them, 

 and it is not altogether surprising that Duncan should have done 

 so. Had he observed them, I venture to think he would not have 

 called the coral a Conocyathus. In his ' Revision of Families and 

 Genera' he places Conocyathus, Trertiatotrochus, and Turhinolia 

 together as closely allied forms ; indeed the perforations of the 

 theca of Trematotrochus form the only feature which separates it 

 from Conocyathus. Now that perforations have been observed in 

 Conocyathus zelandice, we mv^st either amend the definition of that 

 genus, or else remove this species to the genus Trematotrochus. 

 The existence of pores is a character of such importance that the 

 latter coiirse seems to me advisable, and in future Conocyathus 

 zelandice should be known as Trematotrochus zelandice. The 

 specific name is unfortunate and apt to be misleading, as is 

 bound to be the case when a specimen is given a name denoting 

 the locality in which it was originally found, and subsequently 

 appears in other parts of the world. A further consideration of 

 the structure and systematic position of this coral will be found 

 in the systematic part of this paper. 



Family Guyniid^. 



Pyrophyllia inflata Hickson [25]. (PI. LVII. figs. 8-11 ; 

 PI. LYIII. figs. 18, 19.) 



About sixty specimens of this species were obtained on a 

 gravelly bottom at a depth of 156 fathoms in the Gulf of Oman. 

 Professor Hickson has added some further notes to his original 

 description of this species at the end of this memoir (p. 1039). 



Flabbllum magnificum v. Marenzeller [28.] (PI. LVII. 

 figs. 1-3.) 



Corallum fan-shaped, wall and septa very thin and delicate. 

 Numerous rootlets descend vertically downwards, each such 

 rootlet communicating with two interseptal chambers on opposite 

 sides of a septum, and firmly fixed on a mass of mud and 

 serpulid tubes. Calice oval in outline, but constricted in the 

 middle of the short diameter ; practically semi-circular at the 

 ends of the long axis. Two specimens, measuring as follows : — 



II. 



Height 



Calice ( ^°"^ *^''^™®**^^" 



(. Short diameters 



C Greatest width 



\ Least width . . 



Number of septa 



„ „ primary septa 



30 mm. 

 60 ., 



40 

 30 



175 



24 



15 mm. 

 40 „ 



26 

 25 



24 



