604 Proceedings of Royal Society of Edinburgh. [sess. 
Rabenh., Beitr. z. ndh. Kennt. u. Verbreit. d. Algen , Leipzig, 1863, 
Heft i. p. 8, pi. iv. fig. 4), from Honduras and from Peruvian 
guano (Jan., Abh. Schl. Ges. voter. Cult., 1862, Heft ii. p. 4, pi. i. a. 
fig. 5). In Cleve’s collection, at present preserved in the Royal 
Botanical Museum, Stockholm, C. striatus is recorded from Kiel 
Harbour, and specimens from this locality are not unfrequent in 
Rabenh., Alg. Europ., Ho. 1697. 
C. varius. Schum. ( Schrift . Pliys. Oeh. Ges. Konigsb., 1867, 
p. 62, pi. iii. fig. 76), is inadequately diagnosed — the appearances 
described being mostly those resulting from differences in focussing. 
There are about 6J rows of markings in *01 mm. The name 
may be abandoned without inconvenience. 
C.? lieterostigma. Ehrb., Mon. Ber. Ah,, 1872, p. 297. — Specimens 
so named were recorded by Ehrenberg, from a depth of 3 fathoms, 
in the Greenland Sea, near Sabini Island. Ehrenberg regarded 
them as probably belonging to Gallionella. They may be united 
to Melosira. They reached ’0475 mm. in diam., had punctiform 
irregular markings, smaller ones being disposed among the larger. 
C. tenellus. Ehrb., Mon. Ber. Ah., 1854, p. 238. — Diam. *075 mm. 
Markings 8J to 9 in '01 mm., equal ; rows radiating. Specimens 
are recorded by Ehrenberg from the Atlantic Ocean. Ralfs has 
admitted the species, but notes that the characters given are 
insufficient to distinguish it from C. radiolatus and C. subtilis. 
The species may be abandoned without inconvenience. 
Cosmiodiscus imperfedus. Grun ., Denh, Wien. Ah., 1884, p. 69. 
— Grunow refers to this species as figured in Sch., Atl., pi. iii. 
figs. 17, 18. For pi. iii. he means pi. xxxvi. The forms are quite 
distinct from Coscinodiscus pundulatus, though distributed, accord- 
ing to Schmidt, as a var. of this species by Moller. I have 
followed Schmidt in naming them Aidacodiscus suspedus (Rattray, 
Jour. Roy. Micr. Soc. Lond., 1888, p. 339), which I regard as the 
simplest species of the genus Aulacodiscus. Grunow, overlooking 
Schmidt’s earlier name, proposed in 1884 a new one, namely, Au- 
lacodiscus imperfedus, but in the same sentence he notes that the 
absence of processes is opposed to this determination, and so gives 
another name still, Cosmiodiscus imperfedus. The absence of 
processes, however, is not of itself sufficient to exclude the species 
from Aulacodiscus, since these are also entirely absent from A. 
