28 



Perty. Sf, Brasiliense^ Nord., (first discovery of this plant north of the 

 Gulf States). St, rotula, Nord.. (Plate xin, Fig. 9.) St Ophiura^ 

 Lund., in two new varieties, described by the names tetracerum, 

 (four-armed) (Plate xiii, Fig. 4.) and pentacerum, (five-armed) 

 (Plate, XIII, Fig. 5.) All of these were collected in Denmark Pond, 

 New Jersey. St, furcatimi, Ehrb., in Croton water, New York, coll. 

 by R. Hitchcock. St, Pseudosebaldi^ Nord., in Budd's Lake, N. J. 



Staurastrum DivARiCATUM, u. sj). (Plate XIII, Fig. 12.) St. 

 parvum, paullo longius quam latius, granulato-asperum ; sinu lineari 

 angustissimo ; semicellulis subquadratis, angulis superioribus in cor- 

 nu elongatum divaricatum, apice bifido, productis ; a vertice visum 

 forma pentagonali, quinque-radiatum. Diam., sine cornibus, .0015". 

 Hab. In a pond, Hammonton, N. J. Coll. by Rev. H. D. KitcheL 



This species approaches my St, pusillum^ but is somewhat larger 

 and has not 4 but 5 arms, which are not obtuse but bifid. 



Staurastrum coronatum, ;/. sp. (Plate xiii, Fig. 16.) St. sub- 

 magnum, dupla parte circa latius quam longius ; sinu angusto-lineari; 

 semicellulis fere olSovatis, lateribus in cornu incurvum productis, 

 sursum sensim dilatatis, in apice convexo processibus dentiforrriibus 

 in coronam ordinatis ; semicellulis a vertice visis 6-radiatis, in medio 

 coronula papillarum ornatis ; radiis apice subtiliter trifidis, margini- 



bus delicate serrato-dentatis. Long. .0018 ; lat. .0033 ; isth. .001 



Hab. Denmark Pond, New Jersey. 



This plant has the crown-teeth of St, rotula^ Nord., but not the 

 size, number of arms, nor the serration. 



Staurastrum distentum, n, sp. (Piate xiii, Figs, 7 and 7'.) 

 St. mediocre, leve; semicellulis fere obovatis, sursum sensim dilat- 

 atis, apice convexo-crenulatis; angulis superioribus in radium elonga- 

 tum gracilem substrictum productis ; margine non denticulato, apice 

 profunde trifido distento. Semicellulis a vertice visis 5-vel rarius 6- 

 radiatis, apice radiorum tridentato, dilatato, inter bases hastatas 

 sinu profunde lineari. Diam. et long., cum rad., .0016''. 



Hab. Ponds, Sussex Co., N, J. 



The sinus between the hastate bases of the radii, reminds one of 

 my St. pidchrum (Torrey Bull., April, 1880,) but the sinuses are 

 linear, not circular, and the ends of the radii are not obtuse but tri- 

 fid, with the three teeth unusually large and spreading. 



Staurastrum fusiforme, n. sp. (Plate xiii, Fig. 8.) St. sub- 

 magnum, semicellulis angusto-fusiformibus, angulis lateris in proces- 

 sus longissimos achroos margine crenato-dentato apice bifurcato 

 productis ; dorsum sub^cutangulare, crenatum; semicellulis 1 vertice 

 fusiformibus, lateribus in radios rectos, gracillimos attenuatis, apice 



bifido. Diam., cum rad., .005 -.0055" ; long. .0015 



This species appears to be related to St, leptocladiim, Nord., and 

 St. grallatoritan^ Nord., but differs from both in form of cell ; from 

 the former in the length of body, and from the other in the absence of 

 the produced back and the aculei. 



Staurastrum Kitchelii, //. sp. (Plate xiii. Figs. 2 and 2'.) St. 

 parvum, circiter tam longum quam latum, leve ; semicellulis ellip- 

 ticis divergentibus, introrsum ventricosis, dorso plus minus infla^ 

 to. angulis in processus bifurcos productis, a vertice triangulari- 



