46 



The peculiarity of this plant is in the absence of the fimbriae, 

 or spines, except at the angles of the polar lobe, and on the apex 

 of the subdivision next the sinus between the semi-cells. Occa- 

 sionally one or another of the small subdivisions has rudimenta- 

 ry points. Having examined 25 to 30 plants all bearing out the 

 same character, it is deemed worthy of a record. Collected in 

 the same habitat with the preceding. 

 Staurastrum, Meyen, — St. muricatum, Breb, — St. rugulosum, Breb. 



—St. scabrum, Breb. — St. cyrtocerum, Breb. — St. brachycerum, 

 Breb. — St. tricorne, Menegh. — St. leptoceruni, Nordst. — St. 

 cuspidatum, Breb. — St.. asperum, Perty. — St' pygmaeum, Breb. 

 St. echinatum, Breb. — St. Arachne, Ralfs. — St. Sebaldi, Reinsch. 

 These were collected in ponds in Eastern Pennsylvania, and in 

 New Jersey, and were not noted in previous list. The fol- 

 lowing new forms are from the same districts. 



St.pulchrtim^ n. sp. — St. parvum, cytiodermate laevi vel subti- 

 lissime punctato; semi-cellulis introrsum ventricosis, dorso plus 

 minus arcuatis vel rectilinearibus undulato-crenatis : angulis in 

 radium lanceolatum obtusum productis, a vertice pentagoneis, 

 angulis radiatis; radiis hastatis, obtusis, inter basis sinu semicir- 

 culari. Diam. c. rad. .0015^^-0016'' Hab. in lacu, Brown's 

 Mills, N. J. 



St. Nova-Caesareae^ n, spec, — St. mediocre, circiter tam 

 longum quam latum vel paulo longius, granulatum, angulis in 

 aculeos geminos validos subulatos longe productis ; semi-cellul- 

 is a fronte ellipticis, margine ambitu crenato-verrucosis ; a ver- 

 tice quadrangularibus, angulis mammillatis, aculeo gemino im- 



posito. Diara. sine aculeis, lat. .ooi5"-ooi6'' ; long. .0026 

 .003". Cum acul. lat. .oo25"-oo28". 



St. tricormiticmy n, spec, St. magnum, tam longum quam 

 latum, superficie laevi ; semi-cellulis late ellipticis, utroque fine 

 in tres aculeos, achroos, diametro cellulis duplo breviores, di- 

 vergentes, elongatis ; dorso tribus aculeis similibus armatis ; 

 a vertice triangularibus, lateribus modo leviter concavis, modo 

 paullum convexis, angulis in tres aculeos instructis. Diam. sine 

 aculeis .oo36''-oo4"; cum ac. .ooy'^-ooS''. 



St. macrocerum^ n. sp, St. magnum, granulato-asperum, 

 semi-cellulis introrsum ventricosis, dorso leniter rotundati^ vel 

 truncatis ;■ angulis in cornu rectum vel incurvatum provectis ; a 

 vertice polygonis, sex-vel rarius septem-radiatis ; radiis elonga- 

 tis, linearibus, achrois, apice trifido. Diam. c. rad. .oo25"-oo53". 

 Hab. in lacubus, New Jersey. 



St. fascictdoides, n. sp. St, mediocre, dimidio circa lon- 

 gius quam latius, granulatum ; semi-cellulis ellipticis, dorso, 

 rotundatis, ex ventre recte productis, et isthmum latiorem 

 semi-diametro formantibus; a vertice triangularibus; lateribus 

 plerumque rectis, margine prominentiis brevibus, apice 2-4 den- 

 tato vel cuspidato, raunitis; isthmo similiter armato ; angulis 

 truncatis, aculeis duobus vel tribus, acute conicis, instructis 



Diam. lat. .00116 ; long. .0015 



St. sudarcuatum, n, sp. St. mediocre, granulatum, fere tam 



