PLYMOUTH MARINE INVERTEBRATE FAUNA. 185 



[ Foraminifera— co?!<rf. : Porifera ] 



POLYSTOMELLA STEIATOPUNCTATA (Ficlitel & Moll) : WiUwmson, 1858, 

 Kec. For. Gt. Br., p. 42, pi. iii, tigs. 81, 82 (as P. umlnlicaluta). 



Cawsand B. ; Drake's I., and generally distributed, by no means 

 uncommon at the 30-fm. line and outside. 



PoLYSTOMELLA ARCTICA, Parker & Jones: Brady, 1884, "Challenger" 

 lieport, p. 735, pi. ex, figs. 2-5. 



Drake's I. ; Cawsand B., and throughout the district, but much 

 less abundant than either Foli/stonwl/a cri!<pi( or Polii^toinclhi s(ri((tu- 

 punctata ; a complete series of intermediate forms connects these 

 three species. 



PORIFERA. 



Leucosoleniidae. 



Leucosolenia botryoides (Ellis & Solander): J. S. Boiverlank, Monogr. 

 Brit. Spongiadie, vol. iii, pp. 7, etc., fig. 



On the shore between tide-marks, not abundant except in certain 

 localities (e.a.M.) : rocks under the Hoe, in abundance (g.p.B.) : 

 Wembury B., very abundant, on seaweeds, together with Si/co/i 

 compressum (e.a.m.). 



Leucosolenia complicata (Alontagu). 



Fairly common in rock-pools between tide-marks; also in ileeper 

 water off the Mewstone and elsewhere (e.a.m.). 



Leucosolenia variabilis, Haeckel. 



Common everywhere in rock-pools between tide-marks (e.a.m.). 



Clathrinidae. 



Clathrina CORIACEA (Fleming): J. S. Biturrhank, Monogr. Brit, 

 Spongiadie, vol. iii, pp. 8, etc., fig. (as LcucoHolenia). 



Found in small quantities nearly everywhere on rocks between 

 tide-marks ; near ladies' bathing-place ; on rocks under the pier, 

 etc, (e.a.m.): rocks under the Hoe, in abundance (G.P.B.) : Pteny Kks, 

 (w.G. & R.A.T.). 



Clathrina lacunosa (Johnston): J. S. Bowcrlanl; Monogr. Brit. 

 Spongiadte, vol. iii, p. 9, fig. (as Leifcosolenia). 



Occasionally (w.G.): liame-Eddystone Gds., not uncommon (s.P.): 

 only below tide-marks and in deep water (e.a.m.). 



Syconidae. 



Sycon compressum (Fleming): J. S. Boicerhank, Monogr. Brit. Spongiadie, 

 vol. iii, ]). 1, (ig. (as Grantia). 



Common at low water on most rocky stations (s.P.) : ]\lillbay 

 Docks, large specs, (e.j.a., r.a.t., s.p.). 



This form appears to be an annual. The ova develope in Feb., 

 free larvte occur in July, and sponges 3 mm. long in Sept. (g.p.B.). 



Sycon coronatum, Ellis & Solander : J. S. Boivcrhanh, ]\Ionogr. Brit. 

 Spongiadie, vol. iii, pp. 3, etc., fig. (as Grantia ciliata). 



Common at most rocky stations at low water (s.p., e.a.m.): occurs 

 in less exposed situations than S. coinprt^^utn ; common under the 

 Hoe except in autumn (g.p.b.). 



