28 W. B. TUBNEll, FRESH-WATER ALG-ffl OF EAST INDIA. 



ente?, apicibus truncatis, tuberculis 35 — 40, singulatira positis, ornatis. Prope Doc. 

 coronatum Bréb., sed forma et numero tuberculorum differt. 



Long. 540, lat. bas. et apic. 50, lat. centr. semic. 40 /u. T. II, f. 16. 



Somewhat like the preceding species, but a comparison of the apices at once 

 shows the difference; it is also near to Doc. alternans Nordst. (I)esni. Brås. ]>. 205> 

 t. III, f. 36, 1869), possibly a var. of that species. 



Bengal, G. C. W. ; Eåst India, from Utricularia fasciculata , coram. G. v. L. 



5. D. quautillum, n. sp. I). minus, circ. 9-plo longius quam latum, rectnm vel leniter 

 curvatum; regulariter attenuatum, membrana laevis vel levissime punctata, sutura pro- 

 siliente, apicibus rotundato-truncatis, dentibus 6 praeditis, supra tumorem basalem tu- 

 möre minore instruetum. 



Long. 160—195. lat. bas. 16—18, lat. apic. 9—11 ,«. T. II, f. 9; T. IV, f. 12. 



Resembling most Doc. Ehrenbergii, Ralfs (Br. Des. p. 157, t. XXVI, f. 4) from 

 which it difters in the teeth, the general outline, and in being not quite half so large. 

 The form is very common. 



6. D. a?quale, n. sp. D. parvum, circ. 12-plo longius quam latum, rectum; supra tuino- 

 rem basalem tumöre minore instruetum, inde non attenuatum; apicibus perfecte heini- 

 sphaericis. Membrana lsevis; sutura prosiliens. 



Long. 192—216, lat, bas. 17—19, lat. semicell. 12—13 ,«. T. III, f. 11; f. mon- 

 strosa T. II, f. 10. 



This little species seems unique. In shape it is nearest to Doc. (Pleur.) Archerii 

 Delp. [>. 224 (Pl. Candianum, t. XIX, f. 12 — 16!) Desm. Sub-alp. 1877, but nnicli 

 smaller. 



7. D. cylindricum, n. sp. I), mediocre, circ. 10-plo longius quam latum, rectum; margine 

 leviter sinuatum; membrana glabra; apice paullulum expanso, truncato, 38 — 40 tuber- 

 culis parvis instrueto; in diametro rcgulare, vix attenuatum; basi infiatum, et paullulum 

 supra basin; sutura non? prosiliente. Long. 280 — 330, lat. bas. 32, lat. semic. 26, 

 lat. apic. 28 //. T. II, f. 11. 



Frequent in Dr. Wallich's gathering. It is somewhat like D. cristatum, infra 

 No. 26, but differs in outline, in the arrangement of the tubercles, and in the basal 

 part of the semicells. 



8. D. nodulosnm, Bréb. (Ralfs' Br. Desm. p. 155, t. XXVI, f. 1, 1848; Closterium crenu- 

 latumf Ehrb. Verbr. p. 123, t. IV, f. 29, 1843; Doc. et Pleur. crenulatum, auet, non- 

 null.) f. undata, n. f. Fere ut in f. typica sed undulata (extra inflationen) basalem) 

 usque ad apices. Undulationes 7 — 9. Sutura valida, prosiliens. 



Long. 520, lat, bas. 62, lat, apic. 44 //. 



Central India. 



Rabenhorst (Fl. Eur. Alg. III, p. 142) gives the name of Brébisnon as a synon. 

 of Pleur. (Clos.) crenulatum, Ehrb. In this he was probably misled by Ehrb., who 

 quotes (Verbr. 1. c p. 47, No. 25) Bailby's figure in Amer. J. Sci. (p. 302, t. III, 

 f. 32) as the same as his Cl. crenulatum. In this work of Ehrb. the figure is very 

 different from Bailey's, (one segment having teeth at the apex and no basal inflation, 

 Avhile the other has a basal inflation and no apical teeth!). It is very evident that 



