DTCTYOSIPHON 251 



Tetvwnorns, on the same plate, make one think that French examples 

 are fast deteriorating with regard to symmetry and grace. No 

 attempt is made in the figures on the same plate to show the cha- 

 racteristic feature of the genus DocUUwn. On PL vii. a notable 

 characteristic is omitted in fig. 1. Fig. 4 does not represent 

 typical Cosmariiim ccelatum, and fig. 6 is certainly a wonderful 

 C. Holmieme. Fig. 36 b will do for the vertical view of a Staura- 

 strum, the four angles will not do for any Cosmarmm ; the author 

 had better try again to copy Wille's figure (attributed to Leme in 

 the author's description of this plate). The want of symmetry 

 throughout this plate is striking. Just to refer to two things out 

 of many on Plate viii., fig. 1 is a bad drawing of Cosmarium 

 pachydernmm, its chief characteristic being omitted, and C. Brebis- 

 sonii always has twice as many papillae in the periphery as those 

 figured by the author. On Plate ix., fig. 26 a certainly does not 

 belong to the same species as fig. 266. On Plate x., two figures 

 of FjUastrum insigne are given, whose polar lobes are totally 

 different from those characteristic of this species ; and fig. 13 is 

 shocking. On PI. xi. Staurastnim verticilJatum is quite wrong, and 

 has obviously been copied from Cooke. On PI. xv. a figure is 

 given of a species we do not believe in ; the author should compare 



itwith a specimen of Xanthidium antilopcEcum when tlie surrounding 

 mucilage is contracting. Fig. 13 is also no representative of 

 mature X. aculeatum. 



We have not space to comment any further on the drawings ; 

 we are however of opinion that neither Messrs. Petit, Gay, 

 Lemaire nor Gomout would have issued such plates as accompany 

 this work. The author does not appear to have had proofs sub- 

 mitted to him, as the spelling of both generic and specific names 

 requires careful revision. 



W. W. 



DiCTYOSIPHON. 



A PAPER by Dr. Sv. Murbeck, entitled " Ueber den Bau und die 

 Entwickelung von IHctyosiphon fceniculaceus Grev.," appears in the 

 Videnskabsselskabets Skrifter. Mathem.-naUirvid. Klasse, 1900, No. 7. 

 The author divides his work into the following sections : — Growth, 

 Branching, Thallus Cavity, Conducting and Strengthening Tissue, 

 Assimilative Tissue, Cell-tension, Hairs, Hyphfe, Attachment, Re- 

 productive Organs. 



Under these headings the subject has been worked out in great 

 detail, and some facts brought to notice which are interesting in 

 connection with other members of the PhmophycecB. The family of 

 Dictyosiphonacea, is a small one, as defined by Engler & Prantl in 

 Naturl. Pflanzenfamilien, consisting only of three genera — Dictyo- 

 siphon, Gobia, and Scytothamniis. Of these, the first two are repre- 

 sented in the northern hemisphere, and can therefore be conveniently 

 studied and compared, as is the case in the present paper, by 

 European botanists ; the third — Scytothcnmnis — is only recorded 

 from the South Temperate region, and an account of this genus, 



