44 CODIACEAE 
PLATE 9. Codium tomentosum peruvianum 
Photograph of a specimen (Coker 242), from liquid preservative, natural size. 
Our specimens are very dark green and are only 6-10 cm. high, 
at which size they bear gametangia and are apparently mature. 
The peripheral utricles are clavate, 500-1000 и long, 70-240 u in 
maximum diameter, 214-7 times longer than their greatest width, 
truncate, subtruncate, or rounded at apex, which may be very 
strongly or not at all thickened, even in closely adjacent utricles; 
the cuticle is smooth. The gametangia are often paired or occa- 
sionally in verticils of three. 
These Peruvian plants, as our photograph of a fluid-preserved 
specimen well shows, differ obviously from the typical English 
Codium tomentosum in the more complanate thallus and the more. 
congested and more flabellate mode of branching. Under the 
microscope, one is impressed by the usually much thickened apical 
walls, the more strongly thickened of these often having a pro- 
nounced inwardly directed umbo. We have never seen such 
extreme thickening in any European specimens referred to C. 
tomentosum, though Hohenacker’s Meeralgen no. 497 from Cher- 
bourg makes an approach to it in this respect. And the game- 
tangia are rather larger than in the English C. tomentosum. In 
the matter of thickening, the utricles occasionally suggest those of 
the Australian C. galeatum, though scarcely galeate or contracted. 
The utricles of the Peruvian plant have, however, about half the 
diameter of those of C. galeatum and are, at least relatively, longer. 
The thickening of the apical wall of the utricles is even more 
pronounced in C. galeatum, and more uniform, often reaching a 
thickness of 80-95 и even without an introrse umbo, which is 
rarely developed. In general habit, the Peruvian plant perhaps 
resembles the Australian C. galeatum slightly less than it does the 
English C. tomentosum. 
J. Agardh’s description of Codium lineare C. Ag. is in some 
respects suggestive of the plant that we have described above, 
but this can hardly be said of C. Agardh's original description. 
The specimen on which C. lineare was founded J. Agardh suspects 
to represent a monstrous form. ]. Agardh attributes thin-walled 
utricles to C. lineare, which character does not obtain in the 
Peruvian plant. |. Agardh also considers the Brazilian C. decum- 
