18 W. B. TURNER, FRESH-WATER ALG^E OF KAST INDIA. 



7. P. rot un du ni, n. sp. P. min us, circ. duplo longius quam latum, recte ovale; lateribus 

 fere rectis; meinbrana hyalina, glabra; apicibus rotundatis; cellulis non constrictis. 

 Sutura mediana. Long. 48, lat. 25 /u. T. VII, f. 12. 



In shape somewhat reserabling P. spinospermum, Joshua, but is more slender. 

 Only two (infertile) specimens seen. 



8. P. digitus (Ehr.) Bréb. (Ralfs' Br. Desm. p. 150, t. XXV, f. 3; CL digitus, Ehrb. 

 Infus. p. 94, t. VI, f. III). Forma rectum, n. f. 



P. forma? typiese consimile sed lateribus rectis et apicibus magis attenuatis diftert. 

 Long. 440, lat. 80 «. T. I, f. 27. 



In the type the long. : lat. as 5 : 1 in the average of measurements; this form 

 is narrower, or 5V 2 : 1- 



Sonthal district, G. C. W.; near Hydrabad, J. S. 

 f. a typica. Himalayas, Roy in Dickie 1. c. 



9. P. nayicula, Bréb. (Liste p. 146, t. II, f. 37, 1856; P. Berginii, Archer Dnbl. Univ. 

 Zool. Bot. Assoc. Rep. p. 256, t. XI, f. 14, 15, 1858). 



Long. 45—54, lat, 12—13 //. 



10. P. oblongum, De Bary (Conj. p. 73, t, VII, f. 1, 2, 1858) forma major, n. f. 



Forma? typicaa consimile sed versus apices paullo attenuatum. 

 Long. 158, lat, 36 ,«. T. I, f. 22. 



11. P. curtum, Bréb. (Closterium curtum Bréb. in Mengh. Synops. p. 237 (no descript.!); 

 Cosmarium curtum, in Ralfs' Br. Desm. p. 109, t, XXXII, f. 2, 1848; Penium curtum, 

 in Ktz. Spec. Alg. p. 167, 1849; Calocylindrus curtus, De By. Conj. p. 72, 1858; 

 Cos. Thwaitesii d curtum, Klebs. Des. Preuss. p. 27, 1879). 



Long. 40, lat, 19 fi. 

 Northern India; Bengal. 



Sub-genera, The division of the genus Penium into entire and constricted forms, 

 proposed by Gay, Monogr. loc. Conj. 1884, is here (ad interim) accepted. 



A. Holopenium, Gay 1. c. p. 68. Fronds unconstricted. 



B. Sphinctopenium, Gay 1. c. p. 70. Forms constricted in the middle. 



The division is so simple that no typical species need be cited. 



[Note. In all probability the constricted forms will lie, as indeed I think thev should 

 be, relegated to Dysphinctium — as, practically speaking, they might be = a section of 

 Dysphinctium, i. e. elongate, and with apical vesicles. Thev might. tberefore, come next 

 to Docidium, as a section of Cylindrosphinctiwm Nob.] 



Gen. 5. Closterium, Nitzsch, 1817. 



Beitr. /.. Infusor. pp. 60, 67, sec. Aul. 



1. C. acerosiini (Schrank) Ehr. (Vibrio acerosus Schrank Fauna Boica. p. 47, III, 2, 1803; 

 Closterium acerosum Ehr. Abhl. 1831; Infus. t. VII, f. 1, 1838) f, attenuata, n. f. 

 Paulo gracilior quam f. typica; membrana fusco-Iuteola, glabra; laminae qhlorophyllacead 

 circ. 6; nuclei amylacei 7 in una serie. Forma ad (7. peracerosum Gay accédens, sed 

 fere duplo major. 



