1888 - 89 .] Mr John Rattray on the Genus Coscinodiscus. 579 
few isolated rounded granules. Markings rounded, granular, 5 in 
*01 mm., somewhat more crowded around the central space ; rows 
straight, shorter irregular rows around the border ; interspaces 
hyaline. Border distinct, striae delicate. — Ehrb., MiTcrog ., pi. 
xxxv. a. 22. fig. 4; Ralfs. in Pritch. Inf , p. 829; C. scintillans, 
Grev., Quart. Jour. Micr. Sci., 1863, p. 230, pi. ix. fig. 6 (excl. 
C. scintillans , Grev., H. L. Smith, Diat. JSp. Typ ., No. 99. 
Habitat . — Cambridge deposit, Barbados (Browne) ; pancake ice, 
Antarctic Ice Barrier, lat. 78° 10' S., long. 162° W.; lat. 78° 10' S., 
long. 162° W., in 190 fathoms; ex Salpis , lat. 66° S., long. 157° W.; 
lat. 63° 40' S., long. 55° W., in 207 fathoms (Hooker) ; Oamaru 
deposit (Grove ! Doeg !) ; Norway (Deby !) ; Barbados (Cleve). 
Yar. compacta , nov. C. scintillans , Grev. (?) Sch., Jahresb. d. 
Kom. z. Untersuch. d. deutsch. Meer, Kiel , 1874, p. 94, pi. iii. fig. 
33. — Diam. # 04 mm. Central space more inconspicuous, rounded. 
Markings decreasing towards the border, the radial rows more 
crowded, the shorter rows larger than in type. 
Habitat. — Solsvig (Schmidt). 
C. diplostictus , Grun. Van Heurck., Syn. Diat. Belg., pi. cxxxii. 
fig. 3. — Diam. *068 mm. Central space indistinct. Markings 
of two kinds : large rounded granules at wide irregular intervals, 
arranged in inconspicuous radial rows, and becoming somewhat 
smaller towards the border; and minute puncta, least crowded 
towards the centre, also arranged in numerous radial rows, with 
hyaline interspaces opposite the ends of the shorter rows. Border 
sharply defined ; striae distinct, 6 to 8 in 01 mm. 
Habitat . — Balearic Islands (Yan Heurck). 
C. decussatus , Grove and Sturt MS. — Diam. *01 mm. Surface 
flat, slightly convex near the border. Central space circular, about 
of diam. broad. Markings minute, round, granular, with 
unequal hyaline interspaces, most crowded towards the border; 
about the semiradius 6, at the border 8 or 9, in -01 mm.; rows 
straight, secondary oblique decussating rows distinct beyond the 
semiradius. Border narrow, distinct; striae faint, 10 in *01 mm. 
-(PI. I. fig. 7.) 
