Frustulia.] ALOJE DIATOM ACE^. 251 



verse granular yellow mass. Grev. Grev. in Hook. Br. Fl. 

 v. ii. p. 406. Lyngb. Hyd. Dan. p. 110. t. 62. 



^ Parasitic on small Algae in the sea, very common ; investing them 

 with a dense pulverulent covering. 



5. D. elonaatum, Ag. Elongated Diatoma. Filaments with 

 a longitudinal line, the joints ten times longer than they are 

 broad. Grev. Grev. in Hook. Br. Fl. v. ii. p. 407. Berk. 

 Brit.Alg.p. 21. *. 6. 



In pools and ditches, scattered among various Conferva. Near 

 Limerick ; W. H. Harvey. 



6. D. flocculosum, Ag. Flocculose Diatoma. Filaments 

 with a longitudinal pellucid line, the joints transversely striated, 

 nearly equal in length and breadth. Grev. Grev. in Hook. Br. 

 Fl. v. ii. p. 407.Conf.flocculosa, Dillw. t. 28. E. Bot. t. 1761. 



Pools, ditches, &c. ; parasitic on various Conferva. 



* * * Frustula fasciculate or flabelliform. 



7. D. fasciculatum, Ag. Fasciculated Diatoma. Frustula 

 linear, somewhat acuminate at each extremity. Grev. Grev. 

 in Hook. Br. Fl. v. ii. p. 407. Echinella fasciculata, Grev. 

 Crypt. Fl. t. 16. /. 13. 



On marine Algae, frequent. 



8. D. truncatum, Grev. Truncate Diatoma. Frustula linear, 

 truncate at the extremity. Grev. Grev. in Hook. Br. Fl. v. ii. 

 p. 487. Echinella fasciculata, p. Grev. Crypt, t. 16. / 4. 



Pools and ditches, on various Confervas, common. 



92. FRUSTULIA. Ag. Frustulia. 



Frustula linear, free or imbedded in a shapeless mass, solitary 

 or bin ate. Grev. Name, frustula, fragments, of which this 

 plant is wholly composed. 



1. F.fasciata, Ag. Banded Frustulia. Frustula 8 10 times 

 longer than broad, bin ate or solitary, obtuse, terminated at each 

 end by a hyaline globule ; dull ochre with a hyaline central 

 band. Ag. Conspect. Crit. Diat. p. 45. 



In fresh water, mixed with other Algae. Plassey ; W. H. Harvey. 



2. F. Ulna, Ag. Acicular Frustulia. Frustula linear, ex- 

 ceedingly slender, acicular, obtuse, marked with interrupted 

 ochraceous bands. Ag. Consp. Crit. Diat. p. 45. 



In fresh water, mixed with other Algae. Plassey, near Limerick ; 

 W. H. Harvey. The frustula are often of an uniform ochraceous 

 colour, except the apices* which are always hyaline. 



