Figure 6
LM and SEM images of Paralia guyana ‘caisn’ valves. (A,B) VanA4. Light micrographs. (A) Sibling separation valves. (B) A chain of live cells. (C-I) Scanning electron micrographs. Isotype specimens of P. guyana B40 0040794. (C-E) Valve face. (C) Van2B2. Intercalary valve with slightly capitate, long marginal linking spines (arrow) and copulae. (D) Van2B2. Nearly smooth separation valve with a few minute prickles (arrow). (E) Van4A2. Separation valve showing small, abundant prickles (arrow). (F) Van4A2. Interlocked sibling intercalary valves with obscured fenestrae. (G,H). Interlocked sibling separation valves showing variation in size of prickles on the valve face margin. (G) West11B4. Well developed prickles (arrow); most fenestrae of topmost valve unobscured. (H) Van2B2. Minute prickles (arrow); obscured fenestrae. (I) Van4A2. Internal view of valve with irregularly spaced rimoportulae (arrows). Scale bars = 5 μm (A,B,E,F,I), 2 μm (C,D,G,H).