344 SIDNEY J^\ HARMEE. 



PLATE 15. 



Fig. 1. — Lici llaria i,n- a mi i s, Busk, var. prod iicl a, MacGill. Sliowin^ 

 the frontal iiieiiil)raiu; (/. »i.), into which a siiij,fie pair ol' |)arietal muscles 

 (/;. HI.) are iiibcrted ; the plate ciypl. is probably a cryptocyst. The zooeciuiu 

 has f^iveii rise by budding to two younger zooecia {z.'), and is connected witii 

 its lateral neigiibour by the conmiunication pore {c. /;.). Each of the three 

 conmiunicalJon pores is surrounded by a strong calcareous ring; occl., 

 occlusor muscles. — Victoria. 



]<'io. 2. — ]\licroporella malusii, And. Primary zooecium or ancestrula. 

 Tlie frontal membrane is typically Eiustrine, its calcareous margin bearing ten 

 spines, of which three are oral s|>ines. — Naples. 



Fig. 3. — Elustra pisciformis, Busk. Distal view of operculum, showing 

 the vertical flange/.— Bass's Strait (Challenger Collection). 



YiG. 4. — F. pisciformis. An entire zooecium from the same slide. The 

 distal groups of |)arietal muscles {p. mJ) probably act as divaricators of the 

 operculum. 



Fig. 5. — Dimetopia spicata, Busk. The funnel-shaped zooecium is 

 closed by a terminal frontal membrane which is depressed by a single i)air of 

 ])arietal muscles {p.m.). — Victoria. 



jj^j(j_ (3_ — Schizoporel la vulgaris, Moll. Primary zooecium. The region 

 inside the marginal spines is partly occupied by a calcareous plate (c/ypf.), 

 which is probably a cryptocyst. — Najjles. 



Fig. 7. — Cribrilina radiata, Moll. Primary zorecium {p. z.) and three 

 younser zooecia. The Flustrine frontal membrane of p. z. is overarched by 

 a proximal scutum-like s|)ine {sc), while the ten other spines bear minute 

 horizontal calcareous lobes which project from their inner sides. The oral 

 spines of the zooecium z! bear similar lobes. In all except the primary 

 zoceeium the series of oral spines is continued by the pair of elongated mem- 

 branous spines [sp.) on either side of the median |)ore [ni. p.), and further by 

 the small papilla) (.v/;.'), which correspond with the marginal spines of the 

 primary zooecium. The series of pores are in the same radii as these modified 

 s|)ines. The pore-chambers arc not indicated. — Najiles. 



].'|(j_ 8. — Cribrilina ph i lorn ela, I'iusk. The frontal shield is composed 

 of hollow calcareous bars (/. /a), alternately arranged on the two sides of the 

 zooecium. The rows of pores correspond with the intervals between the bars. 

 The compensation-sac {c. s.) and snnu> of the parietal muscles (/;. vi.) are indi- 

 cated. — Marion Is. (Challenger Collection). 



Fig. 9. — Basal view of another zooecium from the same colony. The dista 

 parietal muscles {p. m.') are stronger than the other grou|)s (;;. vi.). 



Fig. 10. — U mbonu la pavonel la, Alder. A series oflarge areolai' occurs 



1 Cf. Gregory (1S93), p. 221. 



