148 THE AMEKICAN MONTHLY [July, 



Fig. 37- — Stan rast rum dctiticidatuni Arch. 



Fig. 2^. — Staurastr 1(1)1 duhiutn nov. sp. (S. submagnum, latius 

 quam longuni, scabro-granulatum, semicellulis fusiformibus, constric- 

 tione, profunda, radiis productis tricuspidatis et inflexis, a vertice tri- 

 angulare, ad basem seinicellula; cum annulo singulo granulorum.) 



This species is nearl}' twice as broad as long, deeply constricted with 

 rough granules, processes inflexed, granulate and tricuspidate, semi- 

 cells somewhat fusiform, base annularly granulate, vertical view trian- 

 gular. 



This will no doubt prove a controversial species ; it is near S. 7nan- 

 feldtii Delp., but smaller and with thicker processes ; it is also more 

 regularly granulate. 



It also comes near 6". pscndosebaldi Wille, but lacks the V)asal infla- 

 tion and the bifurcate spines. 



Fig. zg. — Docidinm. The species has not been determined satis- 

 factorily. 



Fig. 30. — Cosmarium cixlatum Ralfs, var. hcxagoiiuni nov. var. ( Var. 

 cellulis hexagonis, apicibus truncatis tetracrenatis, granulis centralibus 

 in seriebus linearibus ordinatis. ) 



This diflers from the semiorbicular type in having a distinctly hex- 

 agonal form, bearing four of the crenatures of each semicell at the 

 truncate ends ; the central granules are also arranged in linear series not 

 concentric. 



Fig. Tyi.— Cos //I a fin 71/ con trover sum nov. sp. (C. medium, granu- 

 latum, dimidian partem circa longius quam latum, sinu anguste lineari, 

 semicellulis truncato-pyramidatis, granulis concentrice ordinatis, a ver- 

 tice subtruncato-elli])ticis elevatione ccntrali lata, a latere obtuso-ovatis. ) 



Frond granulate, about one-half longer than broad, sinus deep and 

 linea, semicells truncately pyramidal, end view elliptic with a broad 

 elevation at each side, side view obtusely ovate, granules arranged 

 somewhat concentrically. 



Fig. 33. — Staurastriim margaritaceum Meneg. A form from 

 Capcl Curig which shows short spines irregularly disposed at the apices. 



Fig. 33. — Euastrutn crassuf?t Ktz. A form of this species was fre- 

 quent which had a marked protuberance about halfway up the side ot 

 the front view of each semicell. 



Fig. 34. — Micrastcrias /Vv/-?/^;/-/ Ralfs. \xy\. simplex nov. var. (Var. 

 lobis quinque semicelluUe leviter concavis et incisuris brevioribus.) 



This chiefly diflers from the type by having each of the five lobes of 

 the semicell but slightly, concave, and the incision not so deep. 



Fig. 3v — Staurastriim proboscideum var. subgiabrum nov. var. 

 (Var. margine undulato nee spinis truncatis vestitis, radii apicibus in- 

 tegris.) 



This differs from the type in being undulately rough and not adorned 

 with truncate spines, as well as in the entire apices of the processes. 



Fig. 36. — See description of Fig. 5. 



Fig. 37. — Staurastrum cu77ibrici('m var. cambriczim nov. var., forma 

 mino?'. 



It differs from St. Pringsheimii Reinsch in its larger size, and in its 

 relatively sharper spines of varying lengths. It differs from St. senti- 

 cosum Delponte in being longer than broad, whereas the latter is broader 

 than long, and also has its long spines more uniformly arranged. St. 



