170 CRYPTONEMIACE^. v. 



boui'ing genera by the structure of the frond detailed above. In external habit 

 the typical species more resembles the Gracilario, among which it was placed by 

 Dr. Greville ; or the Hypnece (among which, in the Phycologia Britannica, I most 

 unnaturally intruded it) than any of the genera with which the structure of its 

 sporiferous nucleus associates it. In the structure of the frond, as well as in habit, 

 there is a near approach also to Ehabdonia, and to Solieria ; from both which 

 genera, as well as from Gracilaria and Hypnea, the structure of the nucleus 

 widely separates it. This latter character, obviously the first in value as indi- 

 cating natural affinities, brings it into the present Order. Cystodonium purpu- 

 rascms, our only species, is common throughout the Northern Atlantic, extending 

 on the European side from the glacial ocean to the southern coasts of France. 



1. Ctstoclonium piirjmrascens, Kiitz. ; frond terete, sub-pinnately decompound, 

 much branched ; branches alternate, elongate, set with alternately decompound 

 ramuli which taper to each end ; conceptacles lodged in the ramuli, one or more 

 forming nodose swellings in each ramulus. J. Ag. Sp. Alg. 2, p. 307. Kiitz. Sp. 

 Alg. p. 756. Hypnea piirpurascms, Harv. Phyc. Brit. t. 116. Fuctis purprirascens, 

 Turn. Hist. t. 9. E. Bot. t. 1243. /3. cirrJiosa ; the branches drawn out into long, 

 twisted tendrils. 



Hab. On littoral fuci, &c. Common from Halifax to New York Harbour, 

 Squan, New Jersey, 3Iiss E. Morris. /3. Rye Beach, New Hampshire, Miss Froth- 

 ingham. (v. v.) 



Fronds six to twelve inches long or more, as thick as a crow's quill below, attenu- 

 ated upwards, excessively branched and bushy, alternately decompound ; main 

 branches lateral, elongate, spreading, set with two or more series of smaller 

 branches, the last bearing irregularly scattered subulate ramuli: branches and 

 ramuli acute, tapering to the base. Conceptacles imbedded in the ramuli, one, two, 

 or more in each, forming a chain of nodes, the conceptacle being much wider than 

 the place where it is lodged. Colour a dark brownish purple or brown, sometimes 

 pale. Substance between cartilaginous and membranaceous, shrinking in drying. 

 The frond imperfectly adheres to paper. 



^. is a singular form in which the ramuli are converted into spirally twisted 

 tendrils, which coil round neighbouring plants. 



VI. CALLOPHYLLIS. KUtz. 



Frond carnoso-membranaceous, blood-red or rosy, flat, dichotomous or sub-pin- 

 nate, formed of two strata of cells ; the medullary stratum of large roundish cells, 



