26 PEor. V. MARTIN dttncaf's eeytsion op the 



differs decidedly. The costal tubercles are hollow, and communi- 

 cate with the visceral cavity. There is some doubt about the 

 epitheca, some specimens having it according to Lindstrom (see 

 bis elaborate morphological description, op. cit. p. 19.) 



Grenus Ceratoteochus, MM. Milne-JEdwards Sf Jules Haime, 



Ann. des Sci. Nat. Z'^ ser. t. ix. p. 248 (1848), amended. 



Syn. Gonotrochus, Seguenza ; Upifrochus, E. de Fromentel ; 

 OrispatotrocJius, T. "Woods ; Pleurocyathus, Moseley ; Koilo- 

 trochus, "Woods. 



The corallum is simple, subpedicellate, and free in the adult 

 state, eornute, long or short, compressed or not ; calice circular 

 or elliptical. Septa large and usually exsert, or not appearing 

 above the calicular margin. Columella fasciculate. The costse 

 are distinct to the base, and are ornamented or spined or plain, 

 or are hidden and are not ornamented. Epitheca present or 

 absent. 



Distribution. — Fossil. Eocene, Miocene, Pliocene : Europe. — 

 Recent, widely distributed. 



This genus is a Smilotrochoid with a columella fasciculate in 

 character ; and it would resemble many Trochoci/atM were their 

 pali removed. 



Gonotrochus, Seguenza, is merged into Geratotrochus by general 

 consent. 



The genus EpitrocTius, E. de From., Pal. Erang., Zooph. Cret., 

 diagnosed to receive a single specimen of one sjoecies, appears to 

 be a young Geratotrochus, and should lapse. 



Grispatotrochus, T. "Woods, is probably a Geratotrochus. 



Koilotrochus, T. "Woods, Proc. Linn. Soc. New South "Wales, 

 vol. ii. p. 313 (1878) : — Corallum simple, free, without trace of 

 adherence ; no epitheca. Gestae distinct, simple, prominent. 

 Columella rudimentary, confined to a few papillary projections at 

 the base of the deep and wide calicular fossa. Septa four, slightly 

 exsert. 



The calicular fossa is deep and wide. 



Locality not given by Eev. T. "Woods ; but as he refers a form 

 called Smilotrochus vacuus, T. "Woods, to this genus, probably it 

 is a fossil form. Australian Tertiary. 



It appears that this is an aberrant type of Geratotrochus. 



Moseley gives the generic name Pleurocyathus to a form from 



