150 СЕВАМТАСЕАЕ 
PLEONOSPORIUM Naeg. Sitzungsb. Kónigl. Bay. Akad. Wiss. 
München 18612: 339. 1861 
PLEONOSPORIUM VENUSTISSIMUM (Mont.) De-Toni, 
Syll. Аш. 4: 1309. 1903 
Callithamnion gracillimum? Mont. Fl. Boliv. 11. 1839. Not С. 
gracilhmum Ag. Sp. Alg. 2: 168. 1828. 
Callithamnion versicolor Mont. loc. cit. 12. Not C. versicolor Ag. 
Sp. Aly. 2: 170. 1828. 
Callithamnion venustissimum Mont. Ann. Sci. Nat. IV. 14: 172. 
1860. Kütz. Tab. Phyc. 12: 1. pl. І. f. a, b. 1862. 
. On Grateloupia Cutleriae in beach drift, La Punta, region of 
Callao, Jan. 25, 1907, Coker 35 p.p.; on Chaetomorpha, Cladophora, 
etc., in beach drift, La Punta, Jan. 25, 1907, Coker 36 p.p.; on or 
with Glossophora Kunthii, in the surf, San Lorenzo Island, region 
of Callao, Feb. 5, 1907, Coker 57 p.p. 
Dr. Coker's material is from the type locality. The ultimate 
ramification is often more irregular than represented by Kützing's 
figures and some of the ultimate ramuli have occasionally rhizoidal 
prolongations. In no. 57, the segments of the main axes are very 
rarely, as represented by Kützing, of the same diameter at their 
distal end as at their proximal end, but are, in the older parts, 
at least, conspicuously inflated at the base and narrowed above, 
so that their diameter above is sometimes only one half the 
diameter at their base. This diminution in diameter may be 
rather gradual or quite abrupt, giving to the main axis in either 
case the peculiar appearance of being composed of a series of 
superposed flasks. This basal enlargement of the segments was | 
referred to in Montagne's first description of the plant (Fl. Boliv. 
II. 1839), when he identified it doubtfully with Callithamnion 
gracillimum Ag., but was not mentioned when һе finally described 
it as a new species, though it is a conspicuous feature of a part, 
at least, of his original material. In Dr. Coker’s nos. 35 and 38; 
this character is much less pronounced, though distinctly recog- 
nizable in the older parts. In nos. 35 and 38, some of the lower 
segments of the main axis are loosely and imperfectly overgrown 
with decurrent rhizoids; in no. 57, we have not observed any ар“ | 
proach to cortication, though the basal attachment discs аге 
