бы вины РР етерично крие 
ULVA · 21 
of опе ог both layers may divide іп a plane oblique to the general 
surface, so that the extreme margin may become somewhat 
irregularly 3-4-stratose (FIG. 22), with the two outer cells pro- 
jecting a little and the margin itself consequently concave or 
sulcate; or (FIG. 21) one or both of the inner cells in this 3-4- 
stratose condition may bulge out in such a way that the outline 
of the margin in a cross section is subtruncate or rarely rounded- 
convex. It is to be noted also that Montagne, in a rather detailed 
description* of Algerian specimens of Ulva fasciata (Delile’s type 
of the species was from Alexandria, Egypt) states that the margins 
of the thallus are thickened—are, in fact, a little more than 
double the thickness of the central upper part—which is just 
about the reverse of what obtains in these Peruvian plants. 
However, these Peruvian specimens seem to depart even more 
widely from the prevailing conception of Ulva Lactuca and we 
hardly think that the circumstances justify the recognition of a 
separate specific category for forms that are apparently so closely 
allied to U. fasciata. Bory’s Ulva nematoidea from Concepcion, 
Chile, can hardly be said to be costate and the name cannot be 
accurately applied to Dr. Coker’s plant, whether it is considered a 
form, a variety, or a species. However, Montagne,t who main- 
tained U. nematoidea Bory as a species distinct from U. fasciata 
Delile, uniting with it the U. fasciata of Bory, gave (in herb. Mus. 
Paris. an unpublished varietal name to the narrow, costate, 
ruffled plant of Peru (San Lorenzo, Gaudichaud), but as this 
varietal or form name would seem rather inept or even misleading, 
especially when associated with U. fasciata, we trust that we are 
excusable for not taking it up and publishing it for the form 
described above. | 
Dr. Coker’s plants are simple or once furcate near the base 
and are attached to segments of a Corallina by a subterete or 
inversely cupulate basal callus about 1 mm. in diameter; the 
costa is usually 0.5-3 mm. broad; the two layers of the thallus are 
firmly coherent, differing markedly in this respect from a broad 
Ulva that occurs with it—a form that we have referred to U. 
Lactuca rigida. 
Ulva fasciata costata was collected at Callao (in 1839) by the 
ж Expl. Sci. de l'Algérie 1: 151-153. 1846. 
1 Voy. Bonite, Bot. Crypt. 6. 1846. 
