1888-89.] Mr John Rattray on the Genus Coscinodiscus. 515 
His C. fallax (ibid., p. 62, pi. iii. fig. 76) with, in the dry state, 
round markings, between which smaller faint granules, each resolv- 
able under high powers into two, occur, is also C. radiatus, Ehrb. 
In balsam C. fallax , like C. radiatus , showed hexagonal markings, 
and by good illumination smaller granules at their angles. C. caspius , 
Ehrb., was only distinguished by having the rows inconspicuously 
radial and the secondary oblique curved rows evident. Oamaru 
specimens show transitions to C. argus , and have the rows sub fascicu- 
late, with sometimes a distinct central rosette. Schmidt misinterprets 
Ehrenberg’s C. argus , in overlooking the increase of the markings 
outwards ( Atl ., pi. lxi. fig. 13). 
Habitat. — White chalk marl, Caltanisetta; Polirschiefer, Stratford 
Cliff, Va.; Zante, Plattenmergel ; plastic clay, Aegina; tripoli, San 
Francisco, Cal. (Ehrenberg) ; Ichahoe guano (O’Meara !); dredged 
in 1319 fathoms, lat. 71° 19' N., long. 11° 28' W., in yellowish- 
grey mud; in 1300 fathoms, lat. 73° 16' N., long. 15° 48' W., 
in dark greyish-brown mud; and in 569 fathoms, lat. 63° 40' N., 
long. 5° 28' W., in clear grey fine mud (Ehrenberg) ; Caspian Sea, 
14 to 422 fathoms; North Sea, at Cuxhaven ; Baltic, at Wismar 
(Ehrenberg) ; Mors deposit (Schmidt and Cleve !) ; Yera Cruz, 
Mexico (Ehrenberg) ; off Ascension Island, 1845 fathoms, S.S. 
Buccaneer (Grove!); Cambridge deposit, Barbados (Hardman!); 
sounding, lat. 3° 1' S., long. 33° 50' W., H.M.S. Challenger 
(Rae!); “Atlantic Ocean” (Schmidt); Mascara (Cleve and 
Moller !) ; “ Virginia ” (Hardman !) ; Kekko deposit (Grove !) ; 
Oamaru deposit (Grove! Doeg!); Hong Kong and Monte Gubbio 
(Grove!); marine deposit, Fiji Islands (Grove!); Japan (H. L. 
Smith!); “Barbados” (Johnson!); Newcastle deposit, Barbados 
(Grove !); marshy ground from Wedel (Schmidt); Aegina (Schmidt); 
San Benito deposit, California (Grove !) ; Balearic Islands, Sta 
Monica deposit, Patagonia, Delaware, North Carolina (Cleve and 
Moller !); Yedo, Mejillones guano, Bohuslan, mud from Elbing, 
West Prussia, Saldanha Bay guano, Patagonian guano, Schleswig- 
Holstein, Lahuan, Nancoori deposit, Cape Wankarema, between 
Aden and Bab-el-Mandeb (Cleve !); Grip, 70 fathoms; Kiel; Briinn 
Tegel (Cleve) ; anchor ground, Reikjavik, Iceland ; mud from 
Gliickstadt ; Elbe, above Cuxhaven (Rabenhorst and Schwarz !) ; 
coast of St Paul Island, South Sea (von Frauenfeld !) ; Oran marl 
