242 NEMATOGENJS. 



Sphaerozyga Jacobi. Rolfs Ann. Nat. Hist. 1850, 332, t. 8, Jig. 8. 



Forming thick bluish green gelatinous masses, from which 

 the filaments issue in long rays. 



Trichomes elongated, ends attenuated, joints quadrate, then 

 globose, the terminal one longer than broad, and usually conical. 

 Heterocysts sphserical, larger than the joints. Spores oblong 

 or cylindrical, one or two on each side of the heterocysts. 



SIZE. Cells about -005 mm. Spores -008 x '02--025 mm. 



Berkeley in Eng. Bot. ii., t. 2,826, fig. 2. 



Cylindrosporium licheniforme, Kutz. Spec. 292 ? 



In streams, pools, &c. 



We have seen no specimen of this, and cannot say whether it is 

 Agardh's species or not. Although ignored by Continental botanists, it 

 would seem from the figure, which we have reproduced, to be a distinct 

 species. 



Plate XCIV. Jiff. 5. Portions of trichomes with heterocysts and 

 spores X about 400, after Ralfs. 



Sphaerozyga Mooreana. Ralfs Ann. Nat. Hist. 1850, t. 8, /. 12. 



Trichomes scattered, joints minute, somewhat orbicular. 

 Heterocysts minute, barrel-shaped, much narrower than the 

 spores. Spores very turgid, often nearly orbicular or broadly 

 elliptical, much larger than the joints or heterocysts. 



SIZE. Cells about Q035-'004 mm. Spores about -008 x 

 012--015 mm. 



Mixed with other algae. 



" I have only seen imperfect and dried filaments of this species inter- 

 mixed with Nostoc variegatum, Moore ; in a recent state therefore the 

 form of the joints may not agree with the above description, still the 

 large turgid spores must distinguish it from every species but 8. 

 Berkeley ana, and from that it differs in its heterocysts, which are com- 

 paratively much smaller and also longer than broad." Ralfs. 



Plate XCIV. fig. 6. Portion of trichome with heterocyst and spores 

 X about 400 after Ralfs. 



Sphaerozyga leptosperma. Ralfs. Ann. Nat. Hist. 1850, 334, t. 8, 



/. 13. 



Forming large shapeless gelatinous masses, varying from deep 

 green to pale yellowish green. 



Trichomes elongated, not constricted at the dissepiments, 

 joints longer than broad, separated only by transverse dissepi- 

 ments, which are not contracted, and indeed are often so obscure 

 that they can hardly be detected. Heterocysts at first barrel- 

 shaped, finally elliptic, broad at the spores. Spores cylindrical, 

 4-6 times longer than broad truncate, slightly broader than the 

 ordinary joints. 



