PDF file (text) - Cryptogamic Botany Company

Recommendations

Info

168 THE MARINE ALGÆ OF NEW ENGLAND. ODONTHALIA, Lyngb. (From οδους [sic?] [odous], a tooth, αλς [als], the sea.) Fronds dark purple, plane, deeply distichously pinnatifid, with a rudimentary midrib, margin alternately toothed, formed of oblong internal cells and small irregularly shaped cortical cells; tetraspores tripartite, arranged in two rows in short, corymbose, stipitate, lanceolate branchlets (stichidia), which are marginal and generally axillary; cystocarps similarly placed, ovate, with a distinct carpostome and pyriform spores borne on a basal placenta. A small genus of seven or eight species, which are confined mainly to the colder waters of the northern hemisphere. O. dentata occurs in the North Atlantic, extending as far south as Halifax. Several other species inhabit the North Pacific, especially the vicinity of Kamtschatka, one species occurring as for south as Japan and another in California. The species are dark and opaque, and the polysiphonous structure is scarcely visible in the older parts of the fronds, but is clearly seen in young shoots, especially in adventitious growths. O. DENTATA, Lyngb.; Phyc. Brit., Pl. 34. Exs.—Alg. Am. Bor., Farlow, Anderson & Eaton, No. 56. Fronds four to twelve inches long, quarter of an inch broad, decompoundly pinnate, branches oblong, deeply pinnatifid or bipinnatifid, laciniæ alternate, linear, sharply inciso dentate toward the truncated extremities; tetrasporic and cystocarpic branchlets clustered, axillary. Halifax, N. S., and several localities on the Saint Lawrence River. This species has not yet been found within our limits, but may be expected on the Maine coast. It is easily recognized by its color and ramification, and does not adhere to paper in drying. As a rule, American forms of this species are narrower than the common British form, but they are not distinct, and at Halifax the common British form was dredged by Professor Hyatt in abundance. The O. furcata of Reinsch, Contributiones ad Algologiam et Fungologiam, p. 58, Pl. 42 a, is apparently the common narrow form of the present species. RHODOMELA, J. Ag. (From ροδεος [rhodeos], red, and µελας [melas], black.) Fronds dark red, filiform or subcompressed, pinnately decompound, branches filiform, not contracted at base, composed of a monosiphonous axis surrounded by several siphons and a thick cortex of small, irregularly placed, polygonal cells; tetraspores tripartite, borne in the ultimate branches; cystocarps sessile or pedicellate, spores pyriform, on short stalks from the basal placenta. A small genus of dark-colored algæ, confined to rather high latitudes in both hemispheres. It is connected by the genus Rytiphlæa with Polysiphonia. The polysiphonous character of the frond is seen at the tip, and in most species cross-sections of the stem show a circle of large cells surrounding the axial cell and a thick cortical layer. When young the species are covered with dichotomous hairs. The genus is distinguished At sight from Chondriopsis by not having branchlets constricted at the base.
REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. 169 R. SUBFUSCA, Ag.; Phyc. Brit., Pl. 264. Exs.—Alg. Am. Bor., Farlow, Anderson & Eaton, No. 55. Fronds six inches to a foot and a half long, terete, pinnately decompound, branches virgate, lower branchlets patent, subulate, the upper fasciculato-corymbose; tetraspores prominent in subtorulose branchlets; cystocarps sessile, ovato-globose. Var. GRACILIOR, J. Ag. (Rhodomela gracilis, Harv., Ner. Am. Bor.‚ Part II, Pl. 13 c.) Fronds slender; tetrasporic branches distinctly torulose. In deep tide-pools and at a depth of several fathoms. Throughout our whole limits; Europe. A species which varies very much with the time of year and the place of growth. It is. usually common in the spring months, when it is often washed ashore, and in the summer and autumn it is occasionally found, especially in dredging, in a denuded form, nothing remaining but the older branches, which are perennial and which give rise the following season to rather delicate new branches. As usually seen on Cape Ann the fronds are short, robust, and dark colored, even in early spring, while at Wood’s Holl and in Long Island Sound the common spring form is much attenuated, delicate, and of a brighter red color, forming the Rhodomela Rochei of the Nereis. In spite of the difference in aspect, the extreme forms are connected by numerous transitional stages which make it impossible to admit a specific distinction. By Agardh R. Rochei is considered to be the spring form of the typical R. subfusca, but we are more inclined to regard it as the young of the var. gracilior, which is more common south of Cape Cod, the type occurring northward. The species does not adhere well to paper. POLYSIPHONIA, Grev. (From πολυς [polus, many, and σιφων [siphon], a tube.) Fronds filamentous or subcompressed, distichously or irregularly branching, formed of a monosiphonous axis and several (4-20) siphons, often with secondary siphons, and either naked or with a cortical layer of irregular cells, furnished with numerous tufts of hyaline, monosiphonous, dichotomous filaments; antheridia lanceolate in outline, borne on the dichotomous filaments; tetraspores tripartite, in one, rarely in two, rows, in the slightly altered upper branches; cystocarps ovato-globose or urceolate; spores pyriform, on short pedicels borne around a basal carpogenic cell. The largest genus of Florideæ, of which more than two hundred species have been described, but not all of which can be considered valid. They abound in all parts of the world, especially in warm, shallow waters. Some are perennial, but the majority are annual and disappear during the winter. They are easily recognized at sight by the structure of the frond and the tetraspores, which are almost always in a single row in the upper branches, rarely in a double row, and not in swollen special branches or stichidia, as in Bostrychia, which is nearly related to Polysiphonia. The growth is from a single apical cell, from which is formed a monosiphonous axis. By tangential divisions of the upper cells there is formed a number of peripheral cells and a central
Page 1 and 2:
I.-THE MARINE ALGÆ OF NEW ENGLAND.
Page 3 and 4:
REPORT OF THE COMMISSIONER OF FISH
Page 5 and 6:
Page 7 and 8:
Page 9 and 10:
Page 11 and 12:
Page 13 and 14:
Page 15 and 16:
Page 17 and 18:
Page 19 and 20:
Page 21 and 22:
Page 23 and 24:
Page 25 and 26:
Page 27 and 28:
Page 29 and 30:
Page 31 and 32:
Page 33 and 34:
Page 35 and 36:
Page 37 and 38:
Page 39 and 40:
Page 41 and 42:
Page 43 and 44:
Page 45 and 46:
Page 47 and 48:
Page 49 and 50:
Page 51 and 52:
Page 53 and 54:
Page 55 and 56:
Page 57 and 58:
Page 59 and 60:
Page 61 and 62:
Page 63 and 64:
Page 65 and 66:
Page 67 and 68:
Page 69 and 70:
Page 71 and 72:
Page 73 and 74:
Page 75 and 76:
Page 77 and 78:
Page 79 and 80:
Page 81 and 82:
Page 83 and 84:
Page 85 and 86:
Page 87 and 88:
Page 89 and 90:
Page 91 and 92:
Page 93 and 94:
Page 95 and 96:
Page 97 and 98:
Page 99 and 100:
Page 101 and 102:
Page 103 and 104:
Page 105 and 106:
Page 107 and 108:
Page 109 and 110:
Page 111 and 112:
Page 113 and 114:
Page 115 and 116:
Page 117 and 118: REPORT OF THE COMMISSIONER OF FISH
Page 167: REPORT OF THE COMMISSIONER OF FISH
Page 219 and 220:
Page 221 and 222:
Page 223 and 224:
Page 225 and 226:
show all

PDF file (text) - Cryptogamic Botany Company

Create successful ePaper yourself

Delete template?

Save as template?