68 E. GROVE AND G. STURT ON 



C. oculus-iridis, Ehr. (Grun., I.e., pp. 24 and 25). — Diam. 

 observed to "01 2". Cellules at centre about 7 and near the 

 margin 6 in -001". This is rather coarser than the type-form, 

 and is nearer to var. borealis (Bail.), Grun. (I.e., p. 25). Scarce. 



0. bulliens, A. Sch. (" Atl.," PL 61, Fig. 11, also " F. J. L.," 

 p. 20).— Small, about '0025" diam. Frequent. 



G. radiosus, Grun. (" F. J. L.," p. 20, also " Van Heurck 

 Syn.," PI. 132, Fig. 7).— Moderately convex, diam. about •0035' / , 

 no umbilicus, cellules radiant, about 15 in "OOl". — Scarce. We 

 put this here with some hesitation. 



C. oamaruensis, n. sp., Gr. and St. Frequent, but usually in 

 fragments. Large, convex, with small clear umbilicus, sur- 

 rounded by a ring of cellules. Cellules hexagonal, radial, about 

 12 in '001 f at the centre, 15 at the margin, close within which is a 

 ring of puncta about "0004'' apart. At the ends of the inter- 

 calated lines of cellules are minute puncta, which under a low 

 power give the disc a somewhat scabrous appearance, especially 

 towards the centre. Diam. observed up to 'Oil". 



This form approaches C. concinnus, but differs in the much 

 coarser cellulation, which is not punctate, and in the clear 

 umbilicus. 



C. incequalis, n. sp., Gr. and St.— Small, flat, "0025" to •003 // 

 in diam. Cellules hexagonal, radiant, with a slight tendency to 

 a fasciculate arrangement, starting from a point not in the 

 centre of the disc, increasing slightly in size, from 12 at the 

 centre to 10 in '001" at a point about two-thirds of the radial 

 length from the centre, whence they decrease slightly towards 

 the margin, where a distinct ring of very small cellules occurs. 

 Centre furnished with a few rough excrescences, and usually 

 with a conspicuous sub-central tubercle. 



This species resembles the form figured by Schmidt (" Atl.," 

 PI. 57, Fig. 44), but is without the marginal puncta there shown. 



G. decrescens, Grun. (" F. J. L.," p. 28, PL C, Fig. 18).— 

 Small, about "0027" in diam., resembling Grunow's var. repleta. 

 Scarce. 



C. subtilis, Ehr. (Grun., I.e., p. 29, PL C, Fig. 26).— Not 

 common. 



G. subtilis, var. symbolojohora, Grun. (I.e., p. 30, PL T>., Figs. 

 3-6). — Up to '005 " in diam. Has usually a star of four rays in 

 the centre. In other respects exactly as G. subtilis. Common. 



