i .. i.u \uw< i i . .": ; , 



tufted, olivaceous, Bomewhal rigid, the fronds dichotomous ; 



articulations equal in length and breadth ; capsule! oval, 



racemose, pedunculate," Qrev, Scot. Crypt, FL r. 2. I. 96. 

 (Atlas, PL Will. Pig. 80.) 

 Hah. Frith of Forth. Very rare. 



In this species we have the remarkable fact, occasionally 

 met w itli in all departments of natural history, of a Bpecies 

 distinguished bj strongly marked characters having been 



soon but once, and that in xcry small quantity. Tho tuft 



from which Dr. Greville's figure, and the above descrip- 

 tion, which 1 have transferred from his work, were taken, 

 has also served me in making the drawing. The singular 

 grape-like fructification at once marks the Bpecies, and on 



the specimen found almost every thread had moreorless 



numerous clusters. So that it fortunately happens that a 

 small specimen ofthis rarity is &g characteristic as a much 

 larger would be, — no small advantage, when a half-crown 

 would cover all the specimens at present known to bota- 

 nists. # 



XXXIV. ECTOCARPUS. 



80. siliculosus {The pod-fruited Ectocarpus) ; tufts yellowish 

 or pale olive-green, gelatinous, soft; filaments very slender, 

 excessively branched ; ultimate branchlets alternate or Becund, 

 attenuated; utricles stalked, subulate, attenuated to a line 

 point, Lyngb. Hyd. Ban. p. 131. t. 43. (Atlas, PL XIX. 

 Fig. 81.) 

 Ceramium siliculosum, An. C. confervoidee, Jluth. Conferva 



siliculosa, DilliO. 

 Hdb. Parasitical on various marine Alga), between tide-marks, 

 and in :* 1 fathoms water. Annual. Spring to autumn. 

 This is one oi' the commonest species of Ectocarpus in 

 the waters of Europe, and is more 4 generally dispersed than 

 most others of the genua. Formerly it was confounded 

 with K. littoralis, and is still, by many botanists, regarded 

 as merely a state of that species. The branching and ge- 

 nera] habil <>f the two plants are very similar. E. s'tlicu- 

 losus is however usually more slender, more gelatinous, 

 softer, and more feathery in its ramification. A more ah- 

 solute distinction Lies in the difference of {he fruit, which 



* Since this was written, 8. racemOM has D68D found in tole- 

 rable plenty in the Frith of Clyde, by Mr. Roger Eennedy, a 

 jful investigator of the Algse of that estuary. 



