52 DESMARESTIACEAE 
Kiitz.?), are rather thick and rigid (0.17—0.33 mm. thick), and are 
sometimes slightly ridged longitudinally on drying. Their rigidity 
and general habit would suggest the possibility of their being a 
young stage of some member of the family Laminariaceae, but 
the older plants are fertile and the reproductive organs as well as 
the general vegetative structure are of the “ Phyllitis” type. The 
gametangia are slightly longer than in some forms of Petalonia 
Fascia, reaching a length of 40-50 и. ә 
Forms of Petalonia have been reported fromTierra del Fuego, 
Cape Horn, and the Straits of Magellan, but not hitherto from 
Peru, so far as we can discover. 
LI 
Family DESMARESTIACEAE 
DESMARESTIA Lamour. Essai 23. 1813 
Spinularius Rouss. p.p. Fl. Са! ай. 89. 1806 (са. 2]. 
Нетасеа Stackh. Мет. Soc. Imp. Nat. Moscou 2: 58, 89. 1809. 
Hippurina Stackh. loc. cit. 59, 89. 
Hyalina Stackh. loc. cit. 58, 88. 
Desmia Lyngb. Tent. Hydroph. Dan. 33. 1819. 
Dichloria Grev. Alg. Brit. xl. 1830. 
DESMARESTIA PERUVIANA Mont. Fl. Boliv. 35. DL s; $3. 
1839 
? Desmarestia affinis Sond.; Kütz. Tab. Phyc. 9: 41. pl. 97. f. €. 
- I859. 
Dredged in Ancón Bay, Feb. I3, 1907, Coker 9o p.p. (a frag- 
ment only); in beach drift, Chimbote, Feb. 27, 1907, Coker 108 p.p. 
(considerably battered and nearly destitute of monosiphonous 
apices and branches). 
The original collection of this species was made in the neighbor- 
hood of Callao by du Petit-Thouars and (unless D. affinis belongs 
here) we find no record of its collection during the nearly three 
quarters of a century that intervened between its original finding 
and Dr. Coker's investigations in Peru. Dr. Coker's specimens 
are imperfect but appear to be referable to D. peruviana. 
Agardh and De-Toni place D. peruviana under “species inquiren- 
dae." We believe that it is to be compared with the narrower 
forms of D. ligulata, from which it is apparently distinct, being less 
ГА 
