Algm^ 
CALIFORNIA. 
165 
2. Ptilota pectinata. Harv. MSS.; jugamento compresso filiformi subbipinnato, pinnis 
pinnulisque alternis, ramulis extremis (nascentibus pectiniformibus) distichis divaricato- 
multifidis. 
This, too, in its youn^ state, is distinguished like the last by a very beautiful character, a little comb-like 
ramulus, inciso-serrate on its lower side, being placed opposite the insertion of each pinnule ; but in older 
fronds, from a frequent multiplication of this structure, nothing is visible but a confused fascicle of multifid 
ramuli. The pinnules, or secondary branches, are closely set with similar ramuli, alternating with each 
other, and in the spaces between these are situated fructiferous multifid ramuli, which bear dense clusters 
of trisporous capsules. 
Trib. IV. GASTROCARPEiE. 
1. Iridaea papillata. Grev. — Spheerococcus papillatus. Ag. 222. 
A fine species, and an undoubted Iridaa. Shape of I. edulis, thick, flexile, its upper half bearing elon- 
gated papillae in great abundance, each of which terminates in one or more umbiUcated warts. These warts 
contain a mass of small seeds, lodged in a central cavity, and differ principally from regular capsules, (such 
as are found in the Floridem,) by passing into the pediceles, and thence into the frond, without any percep- 
table alteration in the size or shape of the subjacent cellules. The outer coating of the frond also is continued 
round them without interruption, and the whole is perfectly opaque. 
Trib. V. SiPHONEiE. 
1. Codium tomentosum. Stackh. — Fucus tomentosus. Turn. t. 135. 
, Trib. VI. Ceramie^. 
1. Ceramium ohsoletum. Ag. Sp. Alg. 2. p. 145. 
Parasitical on Iridea papillata. 
1. Polysiphonia verticillata. Harv. MSS.; filis nanis repen tibus parce ramosis; ramis 
obsolete articulatis, ramulis subverticiUatis simplicibus acutis incurvis multistriatis articulis 
diametro brevioribus. 
A very curious and distinct little species, 1-2 inches high, with a good deal the habit of Cladostephus, 
but possessing the structure and substance of Polysiphonia. Colour a deep brown. 
