460 DESCEIPTION or [Polygasirica. 



CoccoNEMA (?) Fusidmm = CymleJla affinis (Kiitz.) — Lanceolate, 

 small, attenuate, siibacutc at the ends, and smooth; terminal 

 apcrtiu'es large ; transverse strioe distinct, nineteen in 1-I200tli. 

 Length l-1150th. to l-620th. ; living and fossil. 



C. Cretce = Eunotia Creta. — Striated, narrowly lanceolate, \orj 

 gradually tapering towards each apex, which is acute. Fossil iu 

 chalk marl. 



Genus Cymbosika (Kiitz.) — Individuals either solitary or binatc, 

 stipitate; connected in longitudinal rows by a jelly-like band 

 (isthmus.) 



This genus is a member of the family AcTinanthece ; it resembles 

 Diatoma (Bacillaria, Ehr.y in its mode of concatenation. Its single 

 species is of marine habitat. 



C. Agardhii. — Linear, arcuate, minutely striated ; ends rounded ; 

 stalk very short. Length l-960th. to l-288th. Found on Ceramieae 

 and Polysiphonia, at Venice; and in Tropical America. (P. 17, f. 14.) 



Genus Doryphora (Kiitz.) — Individuals solitary, depressed; se- 

 condary side (regularly punctate) elliptic-lanceolate ; stipitate. This 

 genus, represented but by one species, is a member of the family 

 CocconeidecR (Kiitzing.) — The frustules are attached, by one of their 

 produced ends, to a gelatinous stalk. 



D. Ampliiceros = Cocconeis ampliweros (Ehr.) — Apices produced, 

 rather acute. Found at Citxhaven (P. 17, f. 21.) 



Genus Echinella {The palm-lilce BadUwria.) — Simple, attached by 

 a pedicle (stipes), which is either simple or dichotomously branched. 

 Lorica longer than broad, mostly wedge-shaped, and developed by 

 longitudinal self-division, in fan-like clusters. The chief character 

 of the genus consists in the fact of the self-division not influencing 

 the division of the stalk, for tiie body often divides again without 

 the stalk taking part in the division. Biuing the division of the 

 body, that of the stalk often rests quiet, either pciiodically, or for 

 ever. Young forms of EcJdnella are with difficulty distinguished 

 from species of Gomphonema, and stalklcss ones from those of 

 Synedra, to which latter their organization closely approaches. 



This genus Echinella is not recognized ]iy Kiitzing, who distributes 

 the species enumerated by Ehrcnberg, among various genera; re- 

 taining, however, the major part of Uiem iu the goinis Licmophora, in 



