niEMATOCOCCUS. 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 attaclied to a closely 

 corrugated or ringed mucous appendage. Each gloljule Is 

 usually suiTounded by a single vesicle or ring : In some 

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

 closing vesicles. 



5. H^MATOCOCCUS HOOKERIANA Berk, and Hass. 

 Plate LXXX. Fig. 4. 



Char. Granules vei-j/ small, spherical, blood red, suri-ounded 

 by one or more investing membranes or vesicles. 

 Hab. On a clialk cliff at JNIundley, Norfolk : Sir W. J. 

 Hooker. Dropping Well, Knaresborough : Dr. Alhna?i. 



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 Eev. 

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

 mination by Sir W. J. Hooker. Specimens of //. Allniayii and 

 IT. Hookcriana were then sent to Mr. Berkeley, who satisfied 

 himself of the Identity of Dr. Allmau's specimen with that 

 transmitted to him by Sir William Plooker. 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. ]\I. 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 jMeneghinl'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 



