CHiETOPHORA. 125 



Through DrajKirnaldla tenuis and D. nana there is an 

 easy and natin'al transition to this genus. 



Imbedded in the gehitinous matrix, are usually, in tlie 

 older specimens, a number of stony particles ; these have been 

 supposed to be in some way or other connected with repro- 

 duction. Vaucher regards them as the ruptured cells of the 

 plant, and destined to reproduce the species. 



1. CHJ]:TOriIORA DILATATA Hass. 



Plate XIII. Fig. 2. 



Char. Filaments much branched, fastigiate. Extremities 

 dilated. 



Hah. Ireland : Mr. Moore. 



This species I discovered accidentally, mixed up w^ith a 

 specimen of Nostoc muscorum. It is very remarkable. 



2. Ch^tophora endivi^folia Ag. 

 Plate IX. Figs. 1, 2. 



Char. Mucous matrix someichat compressed, sub-dichofo^ 

 mously branched. Primary \)X2iSi^Q^ fi eciiLently imrallel ; 

 apices of ultimate ramuli ciliated. 



Batrachospermum fasciculatum Vaucher, Hist, des Conf. 

 d'Eau douce, p. 116. pi. xiii. fig. 1.; Harvey in Hooker's 

 Brit. Flor. ii. p. 389. Ulva incrassata, E. Bot. 967. ^f^ ^ 

 ChcEtophora endivicefolia Harv. in Manual, p. 122. u^^u^i^^ 



Hob. Common in streams. -^^«u 



" This Batrachospermum is more rare than the preceding P^^-y^^j^i 

 species B. moniliforme, B. plumosum, and B. glomeratum : it /t^..^ 

 is met with in slowly running w^aters, covering stones, to Avhich /0'' 

 it is attached, under the form of a little green protuberance /\ 4. 

 irregularly lobed at its extremities. It is but little more 0^^ 



than a few lines in length, and about half as broad. It can 

 scarcely be distinguished wdth the unaided sight, but with 

 the microscope it appears curiously composed. If but a very 



