736 Transactions of the Society . 
It is also sufficiently distinct from the genera Dictyosphaerium 
Nag., Dictyocystis Lagerh., and Botryococcus Kiitz. 
Genus Apiocystis Nag. 
A. Brauniana Nag. B., Bn. 
Genus Hydrianum Reinsch, 
H. heteromorphum Reinsch. W. Sk., Angle Tarn. 
Genus Characium A. Br, 
C. Sieboldii A. Br. Near Cockermouth, 
G. ornithocephalum A. Br. Bn. 
Genus Dactylococcus Nag, 
*D. infusionum Nag. Gatt. ein. Alg., p. 85, t. iii. Bn. 
D. Be Baryanus Reinsch. Attached to Cyclops , Bowness. 
Genus Nephrocytium Nag. 
N. Nagelii Grun. R. 
N. lunatum sp. n. Fig. 49. 
N. cellulis lunatis et attenuate, apicibus subobtusis, 
diametro 3-4J-plo longioribus, dorso valde convexo, ventre 
le viter concavo ; familiis e cellulis 4 vel 8 formatis, sub- 
spiraliter ordinatis ; tegumento hyalino, diametro duplo 
longioribus ; contentum cellularum pallidum viride, granu- 
latum. 
Long. cell. 14-18 ^ ; lat. cell. 4-6 yu, ; long, tegument. 
36-60 fi; lat. teg. 20-32 fi. Bn., R. 
This is a very characteristic species, being abundantly distinct 
from the other species. 
Genus Oocystis Nag. 
O. Nagelii A. Br. H., near Windermere. 
0. solitaria Wittr. Hp., Sk., Hk., L. 
*C . crassa Wittr. 
Long. cell. 14-5-15*5 lat. 10-10*5 /*. B. 
*0. Novae Semliae Wille. 
forma major Wille. Bo. 
0. elliptic a sp. n. Fig. 56. 
O. cellulis in familias e 4-8 cellulis formantes consociatis, 
cellulis oblongo-ellipticis, 2J-plo longius quam latius, apicibus 
rotundatis et non-incrassatis. 
Long. cell. 24-25 //, ; lat. cell. 11-11*5 fi . Bt. 
forma minor. 
Long. cell. 15-17 fi; lat. 7*5-8 p. Buttermere. 
This seems distinct from O. Novae Semliae Wille, O , solitaria 
Wittr., &c. 
