THE FRESH-WATER ALG^ OF NORTH YORKSHIRE. 293 



C. ccelatum Kalfs. M., C. — C. ornatum Ealfs. S. — C. Kjell- 

 vianni Wille. Near Moorcock. — C. Blyttii Wille. M. — C. com- 

 missurale Breb. St. — C. quinarium Lund. M. — C. quadrifarium 

 Lund., forma liexasticha Nord. [C. hexastichum Lund.). M. — C. 

 hexalohum Nord. M. — C. cycUcum Lund. M. — Var. angulatum, 

 n. var. This differs from the type in having the front view dis- 

 tinctly subsexangular, and the apices less crenate. Length 50 /x ; 

 breadth QQ fx. M. This was almost as frequent as the type. Some 

 specimens had thek apices almost plane. Fig. 2. — C. sped- 

 osum Lund. M. — C. suhspeciosum Nord. Sc, M. — C, notahile Breb., 

 var. minor Wille. M. — C. orhiculatum Ralfs. M. — C. moniliforme 

 Ralfs. St., M. 



Calocylindrus tuberculatus (Archer) Cooke. M. An extremely 

 rare species. — C. pseudo-connatus (Nord.) Cooke. M. — C. cucurhita 

 D. By. M., C, S., Sc— 0. Thmitesii (Ralfs) Cooke. St., M., C. 

 — C, curtus D. By. M. — C. attenuatiis (Breb.) Cooke. M. — C. 

 strangidatus Cooke et Wills. M. Hitherto found only at Capel 

 Curig, N. Wales. 



Xanthidiiim aciUeatum Ehrbg. C. — X. antilopmim Breb. C. — 

 X. cristatum Breb. C. 



Arthrodesmus Incus Hass. M. — A. hijidus Breb., var. truncatus, 

 n. var. This is smaller than the type, with the extremities 

 shortened ; front view with the ends but slightly concave ; end 

 view as in type. St. Fig. 9. 



Staurastrum dejectum Breb. M. — Var. mucronatum Ralfs. M. — 

 S. apictdatum Breb. M. — S. Dickiei Ralfs. St. — S. cuspidatum 

 Breb. M. — S. aristiferum Ralfs. M. — S. lunatum Ralfs. Sc. — 

 S. oligocanihum Breb. M. — S. avicula Breb. M. — Var. aciculi- 

 FERUM, n. var. M. This has two or more additional small spreading 

 spines between each of the apical angles of the end view. Frequent. 

 Fig. 12.~S. Reinschii Roy. M.— 6'. hirsutim Breb. M., Sc, S.— 

 S. inlosum Nag. M. — S. teliferum Ralfs. M., S. — S. acarides Nord. 

 M. — Var. EBORACENSE, n. var. The lateral incisions are deeper, and 

 almost linear. M. Fig. 8. — Var. hexagonum, n. var. This has 

 the end view sexangular. M. Fig. 7. — S. spongiosum Breb. M. — 

 S. asperum Breb. M. — S. muticim Breb. C, St. — S. orhiculare 

 Ralfs. M. — S. jnjgmcBum Breb. C, S., St. — S. muricatum, Breb. 

 M., C, S., Muker. On both Mickle and Cronkley Fells there were 

 forms of a Staurastrum which I think are very distinct varieties of 

 S. muricatum Breb. The " conic granules " of these varieties are 

 rather spines, one of the varieties having them much denser 

 than in the type. As an empty cell of this last variety could 

 not be found, the arrangement of the spines could not be seen. 

 (I have gathered this last large variety on Helvellyn.) The 

 semicells are also somewhat trapezoid. Length up to 70 /z; 

 breadth to 65 /x. — 8. jnmctidatiim Br6b. Frequent. — S. pileolatum 

 Breb. M. — S. Meriani Reinsch. M. — S. alternans Breb. Sc. — 

 S. Kjellmanni Wille. M. — S. brachiatum Ralfs. M. — S. tricorne 

 Breb. M., St., Cotterdale. — Var. /?. Ralfs. St. — .S'. cyrtocerum 

 Breb. Sc. — S. inflexion Breb. M. — S. j)olymorp)hum Breb. M., 

 C, near Moorcock Inn, S. — S. jmradoxum Meyen. St. — Var. 



