388 NEW OR CRITICAL BRITISH MARINE ALG^. 



terminal tetraspores, and by the more regularly tapering thallus- 

 filameuts. 



Mr. Brebner has sent me from Plymouth specimens of a plant 

 which agrees very exactly with Hauck's description of CruorieUa 

 armorica, but as this name cannot, for the reasons given above, be 

 retained for the plant, I have been compelled to give it a new name. 



12. Cruoriopsis cruciata Dufour, FAenco delle Ah/he della Li(juria 

 — Commentario Cntto(iam.olu(jica Jtaliana, ii. 59 ; Zanardini, Iconnrjr. 

 Phyc. Adv. iii. 25, pi. 8G, figs. 1-4. On old shells dredged from deep 

 water near the mouth of the Yealm, and also from the " Queen's 

 Ground," Plymouth, G. Brebner S E. A. Ii. British specimens of 

 this species agree well with Zanardini' s figure and description 

 of this species, with the single exception that the tetraspores are 

 irregularly divided. Dufour, however, says the genus differs from 

 Contarinia (in which the tetraspores are irregular) only in the 

 position of the tetraspores, which do not form superficial groups; 

 and Zanardini says, " sufficiently clearly cruciate " (Abbastanza 

 chiaramente quadripartite in forma di croce), and, to justify re- 

 taining the species in the genus Criwria, instances lUldehrandtia 

 (where the so-called cruciate tetraspores are really irregular) as a 

 genus in which both cruciate and zonate tetraspores occur. I think, 

 then, I may assume that in C. cruciata the tetraspores are always 

 irregular. According to the late Prof. Schmitz, the real difference 

 between Cruoriopsis and Cruoria lies in the mature cystocarp. In 

 Cruoriopsis the filaments of the gonimoblast are not united, conse- 

 quently free chains of carpospores are formed, as in I'eijssonnelia ; 

 while in Cruoria the filaments of the gonimoblast are united by a 

 gelatinous substance, and consequently the mature cystocarp forms 

 a more or less irregular, compact mass of carpospores. Cruoriopsis 

 cruciata can always be distinguished from C. HaucJiii, described 

 above, by the much smaller lateral tetraspores. 



18. Cruoria rosea Crn. Fl. Finist 147. Contarinia rosea Crn. 

 Ann. Sc. Nat. ser. 4, ix. 72, pi. iii. fig. v. a,b,c. Var. purpurea, 

 nov. var. (Contarinia cruorio'J'orvds Crn. Ann. Sc. Nat. ser. 4 (Bot.), 

 ix. 71, t. iii. fig. iv. a-d? ; Cruoria jnirpurea Crn. Fl. Finist. 147, 

 pi. 18, gen. 123?). Crusts about 200-300 p thick; tetraspores 

 small, lateral, borne near the apices of the erect filaments, otherwise 

 as in the typical form. On old shells dredged from the mouth of 

 the Yealm, G. Brebner. 



The crusts formed by this variety are much thicker than in 

 the typical form, and the tetraspores are produced near the 

 apices of the erect filaments, not at their base, ; but the remains 

 of tetraspores formed at an earlier date are sometimes to be 

 traced at the base of the erect filaments even of the variety. The 

 cells of the basal layer of C. rosea are several times longer than 

 broad, and it is obvious that in a transverse section they would 

 appear very much shorter than in a section cut in the direction 

 followed by the cell-rows of the basal layer. These apparent 

 differences in the size of the cells of the basal layer, the position 

 of the tetraspores, and the thickness of the crusts, seem to be the 

 principal characters which separate C. rosea Crn. from C. purpurea 



