V. CRYPTOXEMIACE^. 181 



into a dense network ; the cortical of moniliform, vertical filaments, set in firm 

 gelatine. Sjwriferous nuclei immersed in the substance of the frond, somewhat 

 prominent toward one surface, roundish, consisting of many confluent nucleoli or 

 masses of minute spores. Tetrasipores collected into dense sori lodged beneath the 

 superficial cells, roundish, cruciate. 



A small genus better distinguished from Iridcea by its external habit and firmly 

 cartilaginous substance than by any structural character. Its type in the well- 

 known Chondrus crispus or Carrageen (Irish moss), a common littoral plant on both 

 sides of the Atlantic. 



1. Chondrus crisjms, Lyngb. ; frond stipitate, flabelliform, dichotomous, fastigiate, 

 fiat, the segments linear-cuneate ; nuclei oval, prominent to one surface of the 

 frond, depressed to the other. J. Ag. Sp. Alg. %p. 246. Harv. Phyc. Brit. t. 63. 

 Kutz. Sp. Alg. p. 735. Fmus crispus, Linn. — Turn. Hist. t. 216, 217. E. Bot. t. 

 2285. 



Hab. Rocks between tide marks, common on the Atlantic Coast from the shores 

 of British America to those of Long Island, (v. v.) 



Fro7id three to six inches high or more, stipitate, the stipes 1 — 2 inches long, 

 narrow cuneate, gradually widening to the first fork. Lamina flabelliform, fixsti- 

 giate, many times regularly dichotomous, with patent, rounded axils ; apices either 

 obtuse or acute. In some specimens the width of the lacinite is only a line or two, 

 and they are neai'ly of equal breadth throughout ; in others the laciniae are half an 

 inch to an inch or more in breadth, decidedly wedge-shaped, flat or very much 

 curled. The substance is between horny and cartilaginous, rigid when dry. Colour 

 varying from a dull livid purple to greenish and yellowish. Sori of tetraspores (like 

 little drops of blood) scattered over the segments. 



& 



2. Chondrus ajfinis, Harv. ; frond stipitate, flabelliform, dichotomous, shghtly 

 concave or channelled on one side, convex on the other ; segments linear-wedge 

 form ; nuclei abundant, scattered through the segments, prominent to both sur- 

 faces. Harv. in Beech. Voy. p. 408. /. Ag. Sp. Alg. 2, p. 247. KUtz. Sp. Alg. p. 

 Til. 



Hab. California, Douglas ; Coulter, (v. s. in Herb. T. C. D.) 



Densely tufted, two to four inches high. Fronds rising with a linear, wedge-form 

 stipes, one to two inches long, and somewhat channelled, then forking, and after- 

 wards repeatedly dichotomous, with patent, linear, or wedge-form, slightly chan- 



