8C, .Mr. A. W. Waters on 



Mamillopora simplex (Koscbinsky). 



Stirhoporina simpkx, Koschinsky, " Bry. der alt. Tert. des Siid- 

 Jkvern?," PaleontoiTvaphica, vol. xxxii. p. 04, pi. vi. ligs. 4-7(1885); 

 Kiikoatrick, " Ilvd. & Polv. Tones Straits," Pioc. Roy. Dublin 

 Soc. vol. vi. p. 623, pi. xvii. tigs. 4 a, b, c, d (1890) ; Waters, " Norlh 

 Ital. Bry.," Quart. Journ. Geol. So(\ vol. xlvii. p. 31, pi. iv. figs. Ki-l)^ 

 (18:>1) ; de .Vn;.felis d'Ossat, ed. A. Xeviani, "C-^ral!. e Bri. JN'eog. di 

 Sardcu- a." Bull. Soc. (tool. Ital. vol. xv. p. 16 (1897). 



Mantillupoya smitli, Calvet, Exp. Sc. du Trav. et du Talisman, Bry. 

 v.l. viii. p. 424, pi. xxvii. tigs. 4, o (1907). 



There are four species called iitichopor'tn<i in the >.'ortli 

 Italian Tertiary Beds, differing principally \\\ the position 

 an:l character of the avicularia. In S. shijjlej.', K., there is 

 on one side above the oral aperture a l:ir<;e trianjiular 

 jivicularium, though very occasionally one on both sides. 

 Kuschinsky thought that the aviculariuiu was below the 

 0!-al aperture, though his fi<jure would suggi-st its being 

 aoove, ap[)arentiy he mistook the zooeciuui to which it 

 l)eloi»ge:l. Tiie second species, S, prufecla, Koscii., has, as 

 de!?cribed by Koseh.insky, a small round avicularium (" knopf- 

 formigcs — mit rundlicher Offnunii) at each side. This 

 small avicularium, according to Canu *, may be pointed. 



The third species [Cupularia) bidento.ta, Kss., has a small 

 round avicularium at the distal end of the zooecium, and the 

 ovicell is very wide, wider than figured by Reuss. Canu 

 also considers that what I determined as S. simplex, Kosch., 

 is the S. prolecia^ K., bnt he seems to have overlooked the 

 fact that Koscliinsky mentioned and figured a large triangular 

 avii-ularinui at tlie side of the oral aperture in S. simplex. 

 S. crassilubris, Kosch, from near Lonigo, Yiceutine, has a 

 projection above the oral aperture, often with a large central 

 process or two lateral ones. 



In neither of the four species mentioned have I seen a 

 central pit, nor is one mentioned, while in [Sticltoporina] 

 renssi, Stol., whi(;h is the type, there is a distinct one, as 

 figured by Stoliczka, and it is verj'^ marked in a s[)ecin!en 

 from Latdorf sent by Pergens. Other dilfcrences are 

 niontioncd on page 82. 



The oral aperture of <S. renssi is much s nailer (about 

 0'08 mm.) than that of the M. bidentata group, in whieh in 

 the wider part the oral aijertui'c, conti'acted at the side by a 

 denticle, is about 0T2 mm. It is thus seen that the group 

 just raentioued docs not correspond with <S. rcussi and must, 

 he placed '.mder Mamillopora, Smitt. Whether S. reussi 

 should be placed with Batopora we may leave open. 



* Bry. Teir. Tert. des Eiiv. de Paris, p. 101 (1907.. 



