KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 25. N:0 5. 87 



58. E. Gangense, n. sp.? E.. ut mihi visum est, E. ansato Focke accedens, sed paullo minus, 

 apieibus rotundatis, profunde incisis; lateribus distincte sinuatis; membrana laevi!, tumori- 

 bus 5 quincuncialiter positis praedita, tumoribus apicalibus nullis; sinu lineari, angustissimo. 



Long. 52, lat. 29, lat. isth. 8 //. T. XI, f. 20. 



This decidedlv resembles Focke's form, and also that of Ralfs 2 a (non b, c), 

 but the other differenees induce me (ad interim) to separate it. 



59. E. spieatum, n. sp. E. mediocre, circ. deeima parte longius quam latum, trilobatum, 

 stelliforme; lobi laterales horizontales, angulis acute rotundatis; sub lobo polari con- 

 strictum, lobo polari capitato-dilatato, apice mcavato, angulis rotundato; semicellulae 

 ventre infläta', anmulo granulorum 6 — 8 granulos includente ornatae; angulis omnibus et 

 angulos versus aculeataé; membrana reliqua laevi; sinu introrsum lineari, extrorsum 

 valde aperto. 



Long. 60, lat. 54, lat. isth. 9.5 ,u. T. X. f. 43. 

 E. hypochondro Nordst. propius. 



60. E. sciilptum, n. sp.? Semicellulae fere semieireulares, incisurae inter lobos laterales et 

 polarem aequales; lobi quoque intermedii et polares rotundati; marginem versus et mar- 

 gine granulis, tumöre centrali inträ annulum granulis ornatum; reliqua membrana la?vi; 

 sinu lineari, sub-angusto, extrorsum ampliato. E. spinuloso Delp. (Desm. sub-alp. 

 p. 85, t. VI, f. 17, 18) * Afrirnno Nordst. (Alg. Xonn. p. 9, t. I. f. 16) proximum, 

 sed multo minus. 



Long. 54, lat. 46, lat. isth. 17 ,«. T. VIII, f. 32. 



I can scarcely think that Xokdstedts form is a sub-sp. of Delpoxtes, it -\vould 

 probablv rank as a species, of which this Avould be a minor form. 



61. E. lons;icolle, Nordst. (Alg. N. Z. p. 33, t. III, f. 5) var. Himalayense, n. v. In scia- 

 graphia fere ut in f. typica, sed multo minus, scrobiculis ut mihi visum est carentibus; tu- 

 moribus parvis 7 in quaque semicellula ornatum (5 basalibus quincuncem positis, et 2 mi- 

 noribus ad apiees); angulis basalibus paullo productis, subacutis. Membrana dense punctata. 



Long. 90, lat, 39 /u. T. XXIII, f. 9. 



From the Himalayas, ex Utricularia stellari, comm. G. v. L. Only one spe- 

 cimen seen. 



The genus Euastrum is a natural link between Cosmarium and Micrasterias; as the 

 genus is nothing more than an incised or lobed Cosmarium the transition between the 

 last-named and the sub-genus Holoeystis is rendered easy and natural. The following 

 seetions and sub-genera mav suffice to classify by form: 

 Section I. Euastrum (sensu striet,). Lobus polaris (vel apex) ineisus. 

 Snb-section a. Lateral margins not, or indistinetlv, lobate. 



Subgenus A. Cosmaiiastrum (yoouriptoi', ornamentum; äoroor, stella). 

 Sinuate or incised at margins; frond circular or oval. 

 Typ. sp. E. orbiculare, coslatum. 

 » B. Colpodastrum (xoAncudrjg, sinuosus; etc). 



Sides sinous; frond oblong, quadrate or pyramidal. 

 Typ. sp. E. ansatum, giganteum, didelta, sinuosum, elegans. 



