OF THE SELENARIADyE, CONESCHARELLINID.fi, ETC. 407 



closely allied should develop into a conical form with small central zooecia, 

 and should have a series of chambers below the zocecia. Put shortly, arc 

 there a number of Bryozoa from different families with quite different 

 zooecial characters which have taken on the same way of growth and sub- 

 basal characters, or have related forms with similar growth gradually 

 assumed more divergent characters ? 



Batopora has small chambers at the lower part, which Reuss and Stoliezka 

 call abortive cells, and these may be homologous with the chambers of 

 Cupularia canariensis and Conescharellina. 



Gregory* would place Batopora under Conescharellina, but Batopora has 

 an oral aperture with a more or less straight lower edge, and a large widely 

 open ovicell— in fact, in most characters it resembles Holoporella, showing no 

 reversal of the position of the zooecia, also the zoaria are more globular than 

 conical. I am not sure that I understand what Gregory meant about the 

 aperture of Conescharellina clithridiata, Greg., which seems to be Holoporella 

 or Cellepora. 



Trochopora, d'Orb. has the whole of the base filled in by a calcareous 

 growth through which pass very long pore tubes (PL 30. fig. 17). This 

 character may not be universal and is discussed on page 418. The base has 

 radial divisions just like those of Lunulites, Cupularia, &c, and in making 

 sections these radial divisions are seen at every stage of the preparation 

 (PI. 29. fig. 18). A specimen of Selenaria nitidaf, Maplestone, in the British 

 Museum, from 22 miles E. of Port Jackson, has the cone entirely filled in 

 with a solid calcareous mass, and in some cases shows radiating lines at 

 the base just as in Trochopora. Ganu & Bassler f place Trochopora and 

 Otionella, Can. & Bassl. under Membraporina §, which belongs to Malacostega, 

 but Lunularia they place with Opesi lidge, that is Coilostega. Tf there were 

 sufficient reason for this it would indicate that the new classification has 

 some weak points, but I fail to find sufficient grounds for separating Tro- 

 chopora from Lunulites. 



Mv conclusions are, that of the forms with discoid or cupuliform growth 

 there are two main divisions with one subgroup. 



(1) Those with the operculum in the frontal membrane, a radial base, and 

 usually no ovicell, including Cupularia, Selenaria, Lunulites, with Selena- 

 riopsis, Maplestone, Trochopora, d'Orb., Otionella, Can. & Bassl., ITeteractis, 

 Can. & Bassl. 



(2) Those with usually a fairly large operculum fitting into the Lepralioid 

 or Holoporellidan oral aperture; with a large ovicell widely open in front, as 



* " Brit. Paleog. Bry.," Trans. Zool. Soc. London, vol. .xiii. pt. 0, p. 251 (1893). 

 t "Results of Deep Sea Investigations,'' Records of the Australian Museum, vol. vii. 

 p. 271, pi. 77. fig. 8(1909). 



% " Tert. Cheil. Bry.," U.S. Nat. Mus. Bull. 90, p. 10 (1917). 

 § Levinsen, "Morpb. Cheil. Bry." p. 144. 1909. 



