24 
NEW OR CRITICAL BRITISH ALGJ£. 
than those near their edges, thus giving to the frond a rough 
war ted appearance. The unilocular and plurilocular sporangia are 
sometimes found on the same individual. 
Swanage. E. M. Holmes. 
Bibliography. 
Algae Britannicae Rariores Exsiccata. Curante E. M. Holmes. 
Fasciculus iv., Nos. 126-150. 
The contents of the sixth part of this excellent collection of 
exsiccata is, as the just confidence we place in Mr. Holmes’ 
judgment and skill in the task of selection would have led us to 
expect, of exceptional interest to all those interested in the study 
of our marine flora. We note with pleasure that Mr. Holmes has 
introduced several improvements into the present part; for instance, 
the labels which accompany the specimens have each printed on 
them either at the top or side “ Holmes’ Alg. Brit. rar. Exsicc.,” 
thus enabling those who distribute the specimens in large Herbaria 
to at once detect the source whence they were derived. The 
Melobesice and other lumpy specimens have also been placed in 
shallow boxes, which is a most decided advantage, as it prevents 
these brittle plants from being injured by the pressure of the 
specimens overlying them. With regard to the specimens them- 
selves, No. 126 is certainly the Ascocyclus orbicularis of Magnus, 
Hauck, and Reinke ; but whether or not it is the Myrionema 
orbiculare of J. Agardh I am unable to say. His description 
(“ Species Algarum,” p. 48) does not agree very well with our 
plant. The sentence “ Ex strato hoc basali surjunt sparsissima 
fila clavata , intermixtis hyalinis confervoideis elongatis ” is hardly 
applicable to the A. orbicularis of Magnus or Hauck. I am 
equally uncertain whether the Myrionema orbiculare of tbe 
Brothers Crouan and French authors generally is referable to the 
Ascocyclus orbicularis of Magnus. Reinke (“ Algenflora der 
Westlichen Ostsee,” p. 46) quotes the Crouans’ figure (“ Floruledu 
Finistere,” p. 25, 165, Fig. 7) as authority for saying that the 
plurilocular sporangia of Ascocyclus orbicularis are sessile. I pre- 
sume, therefore, that he considers the M. orbiculare of the Crouans 
as identical with A. orbicularis of Magnus. Neither J. Agardh* 
nor the Crouans make any mention of the unicellular, thick-walled, 
hyaline utricles which are so conspicuous a feature in A. orbicularis , 
giving to the dried specimens a hoary appearance which alone 
renders them visible to the naked eye. A reference to the Crouans’ 
plate shows that their plant much more nearly resembles A. 
Jcecundvs , var. seriatus, Rke., if it is not actually identical with it. 
It may well be, then, that J. Agardh’s Myrionema orbiculare is 
* Agardh’s “ fila . . intermixtis hyalinis confervoideis elongatis ” would 
seem to refer to the hyaline hairs, not the utricles which he would hardly 
have described as confervoid. 
