— 180 — 



Long. 25,5//; lat. cum proc. 27,5//; lat. isthm. 7,5 p.. 

 In stagnant water in the jungle. 

 Area (of type): Ubiquitous. 



93. S. inconspicuum Nordst. in Acta Univ. Lund. IX, 1873, p. 26, 

 t. I, f. 11. 



Long. 14^; lat. 13«; lat. isthm. 5,2//. 



With the preceding species. 



Area: Europe, N. America, Siberia, Burmah. 



94. S. leptacanthum Nordst. in Vidensk. Medd. Naturh. Foren. Kjø- 

 benhavn, 1869, p. 229, t. IV, f. 46. 



Long. s. proc. 38//, c. proc. 76//; lat. s. proc. 19//, c. proc. 50 //. 

 In muddy ricefields. 



Area: N. and S. America. Senegal. Ceylon. Siberia. 



Arthrodesmus Ehrenb. 



95. A. alatus West & G. S. West, n. sp. (Tab. nostr. Ill, fig. 23-25). 



A. parvus, circiter tam longus quam latus, profundissime con- 

 strictus, sinu angusto-lineari extremo subampliato; semicellulæ late 

 rectangularo-trapeziformes, angulis inferioribus subrotundatis, lateri- 

 bus leviter concavis et sursum divergentibus, angulis superioribus 

 leviter productis, subrotundatis cum spina brevissima minutissima, 

 apicibus late retusis, nonnunquam spinis brevissimis minutissimis 

 paucis 2 — 4 circa angulos superiores; a vertice visæ ellipticæ, polis 

 apiculatis ; membrana delicatissime punctata. 



Long. 25—31//; lat. bas. semicell. 20—25^; lat. apic. semicell. 

 23—27//; lat. isthm. 4,4— 7,5// ; crass. 12,5/^. 



Numerous examples of this species were obtained from amongst 

 Utricularia in a riverbed. They varied a little in their general form and 

 proportions, but the chief variation was in the small spines round the 

 upper angles of the semicell s. The majority of specimens possessed only 

 the apiculations at the upper angles, but others possessed a variable 

 number (from one to four) of small spines arranged approximately in a 

 ring round the angles. 



In outward form it cannot be mistaken for any other species of the 

 genus. 



Hyalotheca Ehrenb. 



96. H. undulata Nordst. in Wittr. et Nordst. Alg. Exsicc. 1879, 

 no. 248. 



Long. 13 — 17//; lat. 5,7 — 6,7//. 



In stagnant water in riverbed. 

 Area: Europe, N. America, India. 



