404 mr. A. w. Waters osf the relationships 



lias avicularia, vibracula, and onychocellaires. Mamillopora probably always 

 lias avicularia. In Cupularia, the muscles are frequently attached to the 

 vibracula by broad bands (PI. 30. fig. 29), instead of by narrow tendons as 

 is generally the case in avicularian mandibles. 



Ovicells. 



No ovicells are known in Cupularia, but ovaria and embryos are found 

 in the zooecia near the periphery (PI. 30. fig. 25), nor are any known 

 generally in Selenaria, though the late 0. M. Maplestone, in a letter, wrote 

 that in specimens from Queensland he has seen the ovicells of S. concinna 

 resembling those of Conescliarellina philippinensis. In Conescliarellina philip- 

 pinensis there is a raised globular ovicell as described by Whitelegge*, and 

 I have some in my collection, though, out of some hundred specimens, 

 ovicells have only been seen in two or three. The ovicell, like the oper- 

 culum, is directed to the centre of the zoarium in a puzzling manner. 

 Conescliarellina eocosna, Neviani, also has ovicells. 



In Mamillopora simplex, Kosch., the ovicell is a raised inflation and is 

 widely open, as in Haloporclla. In Orbitulipora petiolus, Lonsd., tbe ovicell 

 is also globose. Smittf figures it in Mamillopora cupula, Sm. ; Reuss and I 

 have described it in Batopora multiradiata, Rss. " Cupularia hidentata," $ 

 Rss., also shows an ovicell, but from the figures it was not clear to what 

 genus it belongs, but now it is found to be Mamillopora, closely allied to 

 M. simplex, Kosch. 



Most of the published figures of the earlier authors gave the Selenariadae 

 upside down, whereas in such genera as Cupularia, Selenaria, Lunidites, 

 the distal end with its Membraniporidan aperture should be shown at the 

 top. Maplestone |j, when dealing with Conescliarellina,, says, in accounting 

 for the position, " the free edge of the operculum is directed towards the 

 apex, but it is not the distal edge. The fact is that the operculum is hinged 

 at the distal end and not at the proximal one ; so that- in the conical forms 

 not only are the zooecia upside down but the operculum is also upside down." 

 Difficult as it is to understand this reversal it seems to be the case in Con- 

 escliarellina, but not in Cupularia, Selenaria, or Lunulites. 



Whitelegge §, Haswelll, and Maplestone**, call attention to the semi- 



* "Australian Poly." p. 342. 1887; see also Maplestone's " Biporfe," p. G, pi. 1. fig. 2 

 (1910). 

 t Floridan Bryozoa, pi. 2. fig-. 33 ; pi. 7. figs. 146, 147 (1873). 

 % Waters, "Batopora," p. 87, pi. 6. figs. 7, 11 (1919). 

 il " Growth and Habits of Biporse." 

 § " Australian Polyzoa," p. 339. 1877. 



% " Polyzoa from the Queensland Coast," Proc. Linn. Soc. N.S.W. vol. v. p. 42 (1881). 

 ** " Biporas," p. 5. 1910. 



