502 MR. A. W. WATERS ON 



have been able to see the zooecia superimposed, so that both lateral 

 and distal walls of the upper layer are above the similar walls of 

 the lower layer*. Reuss has shown the same thing in Gtimuli- 

 pora angidata v. M., and I have in previous papers referred to it 

 in Melicerititidse, 



In some other species of ScJikoporella the superimposed layers 

 gi-ow quite differently (see p. 504). 



Loc. Add : " From bottom of S.s. ' Juba,' which always remains 

 in Zanzibar waters " (511), collected by Crossland. 



SCHIZOPORELLA PERTUSA Esper. 



See Miss Jelly's Catalogue, and add : — 



Lepralia pertusa Calvet, " Bry. Mar. de Cette," Trav. Inst, de 

 Zool. de rUniversite de Montpellier, ser. 2, vol. i. p. 51 ; " Bry. 

 Mar. de Corse," op. cit. vol. ii. p. 26 ; JuUien & Calvet, " Bry. 

 prov. des Camp, de I'Hirondelle," pp. 69, 134. 



Schizoporella pertusa Calvet, " Exp. Sc. du Travailleur et du 

 Talisman," p. 416. 



Loc. British ; Labrador ; Atlantic ; Florida ; Mediterranean ; 

 Mazatlan ; Australia ; Samoa ; China Seas. Wasin, Brit. East 

 Africa, 10 fath. (500) (520), collected by Crossland. 



SCHIZOPORELLA NIVEA Busk. (PI. LXX. figS. 1-3, 7-9, & 



PI. LXXIII. fig. 16 ; and text-fig. 80.) 



Schizoporella nivea Busk, Zooh Chall. Exp. voh x. pt. xxx. 

 p. 163, pi. xvii. fig. 1 (1884) ; Philipps, in Willey's Zool. Results, 

 pt. iv. p. 440 (1889); Thornely, Ceylon Pearl-Oyster Fisheries, 

 vol. iv. p. 114 (1905); Rec. Indian Mus. vol. i. pt. 3, no. 13, p. 189 

 (1907); Waters, Rep. Mar. Biol, of the Sudanese Red Sea, 

 " Bryozoa," Journ. Linn. Soc, Zool. vol. xxxi. p. 168, pi. xvii. 

 figs. 2-4 (1909); Thornely, " Mai\ Poly, of the Indian Ocean," 

 Trans. Linn. Soc, Zool. vol. xv. p. 148 (1912). 



Zoarium in Hemescharan form. Zooecia quadrate, distinctly 

 separated, fairly large pores over the surface, an aviculai-ium 

 near each upper corner with broad triangular to nearly semi- 

 circular mandibles, sometimes a small avicularium at one of the 

 lower cornei-s, Below the aperture there is frequently, in the 

 older zooecia from (501), a mucro which may be long spreading 

 out at the ends, or there may be a thin lamina radiating in four 

 directions the whole length of the mucro. These mucros are 

 moi"e frequent on the ovicelligerous zooecia. The oral ajjerture 

 is nearly circular, has a wide poster, and there are fine lines 

 across the operculum (fig. 2). 



The ovicell is large, raised, globular, with a ridge from the 

 middle of the proximal edge, shortly bifurcating to each side, at 

 any rate in the older zooecia. The pores over the surface of the 



* Reuss, " Zui- Fauna des deutschen Oberoligocans," pt. ii., Sitzb. d. k. Akad. der 

 Wissensch., Wien, math.-nat. CI., vol. 1. Abth. 1, jj. 644 (31), pi. ix. iig. 1 (1864) ; 

 " Die Foram., Anth. und Brj'ozoen des deutecheii Septarieiitliones," Deiik. s. d. 

 k. Akad. der Wissensch., Wicii, math.-nat. CI., vol. xxv. p. 179 (63), pi. viii. fig. 12 

 (1865). 



