BY G. I. PLAYFAIR. 117 



Lismore(17, 20, 21). In profusion(17). 



Cf. Cleve, Diat. Finland, p.51, PI. iii., f.8, 9. A very rare 

 species, known (living) only from Finland, and fossil in Sweden 

 from freshwater deposits of the Ancylus epoch. Striie 24-25 in 

 10 /x according to Cleve, Syn., ii., p. 17 4. Va,v. pulcher^nma 

 sometimes approaches in shape to Ach. Hungarica Grun. 



Genus Cocconeis (Ehr.) Cleve. 



COCCONEIS PLACKNTULA Ehr. 



" Intus et extus isevis," Kiitz., Bac, p. 73. 

 Long. 22-36; lat. valv. 14-22, crass. 3 /x. 

 Lismore. Cum sequenti. 



Var. EUGLYPTA (Ehr.) Cleve. (PL iv., f.28). 



Forma utrinque ad lineam mediam striis longitudinalibus 

 crassis rectis 5-6 ornata. Dimensiones et cetera ut in forma 

 typica. 



Lismore(l, 6, 13, 17, 18, 20, 21, 22); both forms intermingled. 



Var. LINEATA (Ehr.) Cleve. 



Forma major, striis longitudinalibus 5-6 iindtdatis ornata. 



Long. 40-46; lat. valv. 26-30; lat. annul. 3 /x. 



Lismore(l, 6, 15, 20, 21). Cum f. typica rarius. 



The wavy longitudinal strise are an optical illusion caused by 

 the transverse striae decussating at a very obtuse angle. Cleve, 

 Syn., ii., p.l69, gives long. 40-70, lat. 30-40 /x for this form. 



Var. AUSTRALICA, n.var. (PI. iv., f.29). 



Var. lineatse consimilis, striis autem nullis ; area centrali 

 (1 nodulo) circular! distinctA, instructa, lineis medianis binis 

 arcuatis. 



Long. 44; lat. valv. 30 /x. 



Lismore(l). Rarissime. 



Genus Epithemia Br^b. 

 Epithemia gibberula var. perpusilla, n.var. (PI. iv., f.30). 

 Var. productse consimilis sed minor; costis 5-6 dorso crassis ad 



zonam versus sensim attenuatis. ■ = <. /X 



Long. 15-16; lat. valv. 6; lat. frust. 13, ap. 4 /x. '^'-•'^■O^ 



.^y 



