650 MB. W. JOSHUA ON BUBMESB DESMIDIEiB. 



Thickness without papillae 15 jm,; length 25 jn; breadth 23^; 

 breadth of isthmus 6 fi. 



C. Hammebi, Beinsch. 



C. betusum, Perty. 



C. venustum, Breb. 



12. PLEUBOT^NruM, Naeg. 

 P. nodosum, Bailey. 



P. CLAVATUM, jffttto. 



P. indicum, Chun. 



P. INDICUM, f. MINOB. 



13. Docidium, Breb. 



D. Baculum, Breb. 



D. gbanulifeeum, n. sp. (Plate XXV. figs. 11 & 12.) 

 D. magnum, diametro 14-15-plo longius, ad basin eemicellulffi 

 nflatioue subhemisphaerica indistincte undulatum, ajneibus trun- 

 catis angustioribus : membrano crasso, granulis magnis regula- 

 riter obtecto, gramilis singulis fere sphayricis, centro nodulosis: 

 zygospores ignotis. Longit. 680-885 n, latit. apud apicem 35- 

 40 fi : inflations latit. 45-60 fi : latit. in centro semicellula? 

 45-60 /j. : granulatioues 3 in 1 ju. 



Large ; 14-15 times longer than wide, with a subhemispherical 

 inflation at base of semicell ; indistinctly undulated ; apices trun- 

 cate, rather narrowed ; membrane thick, regularly covered with 

 large granulations ; each granule nearly spherical, having a 

 central nodule ; zygospore unknown. In size and shape resem- 

 bling Pleurotcenium maximum, lleinsch. Length 680/i-885/i; 

 width at apex 35 yu-40 fi ; width of inflation 45 /i-60 \i ; width in 

 middle of semicell 45 ^z-60/j ; granulations 3 in 1 \i. 



D. tessellatum, n. sp. (Plate XXV. fig. 15.) 

 D. mediocre, diametro 8-9-plo longius, a medio ad apicem, vax 

 angustatum, pra3ter apices, projectionibus magnis irregularibus 

 quadratis, sursum deminutis, obtectum : membrano non punctato : 

 apice leviter angustato, spinis 8-9 truncatis exsertis instructo- 

 Longit. 200-330 p, latit. 25-35 fi : apicis latit. 16-24 /;. 



Medium size ; 8-9 times longer than broad from middle to 

 apex, scarcely narrowed, covered with large irregular quadrate 

 projections not extending to apex, but diminishing in 8ize 

 upwards ; membrane not punctate ; apex slightly narrowed, 



