678 
Proceedings of Royal Society of Edinburgh. [sess. 
Artificial Key. 
Markings punctiform. No costae. Proximal portion 
of process columuar, barbadense. 
Markings areolate. Evident radial costae. Proximal 
portion of process nodular, costatum. 
PEPONIA. 
Grey., Trans. Micr. Soc. Lond ., 1863, p. 75. — Central portion 
roundly elliptical, rarely subquadrate, with obtuse angles and 
convex sides, opposite the extremities of the minor axis a small 
regular cone, with free end rounded. Surface subplain. Colour 
pale grey. Central space absent. Markings areolate, sometimes 
increasing slightly from centre to semiradius, and again decreasing 
to border; between the lateral cones and the central portion a 
narrow hyaline band, at the extremities of the cones a small round, 
hyaline area. Border narrow, hyaline. 
P. barbadensis. Gr'ev., Trans. Micr. Soc. Lond., 1863, p. 76, 
pi. v. fig. 25. — Central portion with major axis from *0375 to 
*075 mm.; distance between apices of lateral cones ’0475 to 
•0925 mm. Markings towards the centre 4, at the semiradius 3|, 
at the border 8, in ’01 mm., without order or in inconspicuous 
radial and short oblique rows ; on the lateral cones decreasing 
towards their apices, sometimes absent. 
Habitat . — Bridgewater deposit, Barbados (Johnson !) ; Cambridge 
deposit, Barbados (Johnson! Greville) ; “Barbados” (Johnson! 
Greville !). 
