1LEMATOCOCCUS. 325 



This very fine species I have never met with in any con- 

 siderable quantity. Scattered isolated globules I have fre- 

 quently met with, and these occasionally attached to a closely 

 corrugated or ringed mucous appendage. Each globule is 

 usually surrounded by a single vesicle or ring : in some 

 globules, however, there are as many as four or five en- 

 closing vesicles. 



5. HyEMATOCOCCUS HOOKERIANA Berk, and HttSS. 



Plate LXXX. Fig. 4, 



Char. Granules very small, spherical, blood red, surrounded 



by one or more investing membranes or vesicles. 

 Hob. On a chalk cliff at Hundley, Norfolk : Sir W. J. 

 Hooker. Dropping Well, Knaresborough : Dr. Attman. 



Shortly after noticing this species in beautiful condition, 

 mixed up with H. Allmani, but which had altogether escaped 

 the notice of Dr. Allman, I received a dried specimen of 

 this plant, accompanied by a description and remarks on the 

 ringed organization of the mucous appendages from the Bev. 

 M. J. Berkeley, to whom it had been communicated for exa- 

 mination by Sir W. J. Hooker. Specimens of H. Allmani and 

 H. Hookeriana were then sent to Mr. Berkeley, who satisfied 

 himself of the identity of Dr. Allman's specimen with that 

 transmitted to him by Sir William Hooker. The only differ- 

 ence between the specimens collected in habitats so widely 

 different was, that in the former the transverse corrugation 

 of the sheath was the more conspicuous. 



The Rev. M. J. Berkeley, in his first letter, thus speaks of 

 it: " I have just received the enclosed from Sir W. J. Hooker. 

 It does not agree with any of Meneghini's species of Micro-' 

 cystis. There is a very curious appearance in some parts as 

 if the old vesicles were chained together." In a second com- 

 munication, Mr. Berkeley adds " I have not had time to ex- 

 amine your Alga till to-day : it is certainly the same as Sir W. 

 Hooker's, but far finer ; the threads are three or four times 

 as long. I still fancy my theory, as to their origin, is right." 



Y 3 



