1 18 W. Ii. TURNER, IKENI1-WATER ALG.E OF KAST INDIA. 



Beng. |>. 11)1, i. VII, 1860). FoUowing the example of L)h. Nordstedt, in N. Z. 

 Alg. p. 27, I thus arrange the forms of this species: 



ci. genuina Nordst. Cellulae margine fere integrae, sub-rectae, saepe crenulis 2 distan- 

 tilms minutissimis ornatse. Sporae late ellipticae. 



F. minor (Aptogonum Baileyi, Ralfs Br. Desm. p. 208, t. XXXV, f. 1 ; Desm. 

 Baileyi Wolle Desm. U. S. Amer. p. 27, t. II, 8, 9, 12?; Nordst. 1. c t. II, f. 4, 5). 

 Long. 19—22, lat, 22—24 /it. 

 Not vet noted from India. 

 F. major (Wolle) 1. c. f. 10, 11). Zygospore large, oval. 



Long. 30.15— 35, lat. 36—44, zyg. diam. 36 X 22 ,//. T. XIX, f. 11. 

 Bengal, in Wallich's material. 



var. />'. Bengalense Nordst. (1. c. p. 27; inclus.? D. tetragonum Delp. v. excavatum 

 Schaar. Afgh. Alg. p. 247, t. V, f. 25; Apt. Baileyi Wallich Desm. Beng. ex p., 

 t. VII, f. 7, 9?). Cellulae margine medio late exeedente (crenis parvis?). Sporde 

 fere circulares. O. N., 1. c. 



Long. 20.5, lat. 23 ,w, G. C. W. 



18 , » 23, diam. zyg. 18.5 //. T. XIX, f. 10. 



y. coelatum (Kirchn.) Nordst. (Desmidium coelatum Kirch. Alg. Schles. p. 133, 1878; 

 Aptogonum sp. Wallich Mscr. No. 55, ex p.) 



a. Cellulae margine medio irregulariter incavatue. 



F. trigona, tnmid at the sides and not constricted under the angles in vert. view; 

 F. 4-gon;i in the same view with the sides a little incurved. Connecting processes 

 circnlar in the Indian speeimens. 



Java, Nordst. Alg. Char. p. 4; Bengal, G. C. W. Long. 17— 19, lat. 22— 23 u. 

 In this form the eentre is not distinctly incised, but rather incavate. 



b. Cellulae margine medio incisas. 



F. Italica (Rac.) Nordst. 1. e. (Aptog. coelatum B var. 3-gonum a, Racib. Desm. 

 Polon. p. 6Q; Apt. Baileyi, Delp. Desm. subalp. p. 62, t. III, f. 16—19). Cellulär 

 a vertiee visas convexae vel lateribus subtumidis. 



This seems to be an ordinary 3-angled form with incised sides, and it is härd 

 to comprehend why Raciborski did not include the quadrangular form {Apt. tetra- 

 gonum Delp. 1. c. p. 63, t, III, f. 20 — 23) also under bis /. Italica. The diffe- 

 rence is hardly suffieient to constitute a Variety'! 



c. f. Polonica, (Rac.) Nordst. 1. c. (Apt. coelatum B var. triy. b, f. Polonira Racib. 

 1. c, t, 5 (XIV) f. 6. Cellulae a vertiee visae lateribus subconcavis. 



This is a very curious form, the eoncave sides being unique for this species. 

 b and c not noted from India. 



<V nndulatum (Maskell) Nordst. 1. c. (Aptog. undulatum Mask. N. Z. Desm. p. 302. 

 t. XI, f. 1 — 4; non D. undulatum Corda). Cellulae margine convexo leviter angu- 

 lato-triundulata'; a vertiee visa- regulariter triangulares angulis rotundatis, lateribus 

 fere rectis. Nordst. 1. c. t. II, f. 8. 





