Howe: PHYCOLOGICAL STUDIES 495 
a species, and it appears that the earliest available name for it that 
conforms with prevailing rules of nomenclature is Halimeda 
discoidea Decaisne,* under which name the species is described 
below : 
HALIMEDA DISCOIDEA Decaisne, Ann. Sci. Nat. II. 18: 102. 
1842. 
? Halimeda papyracea Zanard.{ Flora 34: 37. 1851; Mem. R. 
ast. Ven. 7: .288.: ph S30 Judea tBEe: 
Of a light bright-green color and lubricous when living, becom- 
ing yellowish- or albescent-green and more or less pergameneous 
or papyraceous and smooth to the touch on drying, suberect or 
decumbent, 5-15 cm. in height or length, subsessile, very lightly 
calcified, the calcification usually confined to the narrow area lying 
between the coherent ends of the peripheral utricles and the distal 
ends of the subcortical utricles, in the oldest parts sometimes in- 
* The name Cora//ina discoidea Esper (Pflanzenthiere, Fortsetz. 2, Corallina, pl. 
tf. 1798-1806) appears to have fallen short of effective publication according to both 
the Vienna and the Philadelphia codes of nomenclature, so may be ignored in deter- 
mining the correct name of the present species, whether Esper had this species before 
him or not. The name first appeared on a plate, illustrating a large Halimeda of the 
Tuna group, without analysis of parts and without descriptive or explanatory text. In 
@ continuation of Esper’s work by F. L. Hammer, many years later (3: 356. 1830), 
t See footnote on following page. 
