123 



fronto lineari - ellii>ticum vel lamoolatum , utroquc fine acutiuscu- 

 lum. v. v. 



Long. ' Mt— W = 0,0008— 0,0052'', 



b. forma minor, ' m/" Umga. (1). vitreum Ktz. 1. I.). 



e. forma minima, '/341 — ' ji ;.-,"' longa. (D. minimum Ralfs in 

 Trans. Bot Soc. of Edinb. II. p. 20. Sm. 1. 1. F. 313.). 



Hab. in algis marinis ad oras Europae. 



XXVII. Diiiieregrainiiia Pritch. ( 1861 )-. Fmstula 



quadrangula in fascias arcte conjuncta, sub polis constricta ; valvae undu- 

 latae, transverse striatae , nodulo centrali destitutae ; striis medio vitta 

 vel area longitudinali interruptis. Conf. Fig. nostr. 36. 



(Denticulae spec. Gregory ex parte). 

 a. Frustula latere medio dilatata, sub polis constricta. 



D. minor Pritch. (Inf. 790. Grun. in Wien. Verh. 1862. p. 376. 

 T. VII. F. 29. Dentieula minor Greg. Diat. of the Clyde p. 22. T. II. 

 F. 35.). D. parvum, pauca in fascias conjuncta, valvis anguste rhombeo- 

 lanceolatis, costis 15 — 20 in 0,001". 



Long. ■ 148'" =" 0,0005". 



Hab. in Lamlash Bay et Loch Fine Scotiae (Gregory) , in fundo 

 maris adriatici (Lorenz). 



D. capitatum Pritch. (1. 1. Denticula capitata Greg. 1. 1. F. 31.). 

 D. robustum, apicibus rotundatis, valvis late lanceolatis, apicibus obtusis, 

 striis subtilibus 19—24 in 0,001". v. s. 



Long. Vso— V38 ;// = 0,0017— 0,0023"; lat. max. Vi53"' = 0,00058". 



Hab. in Loch Fine Scotiae, Cap Martin prope Mentone (Boettcher). 



D. nanum Pritch. (1. 1. T. IV. F. 33. D. Gregoriana Grun. 1. 1. 

 T. VII. F. 21—23. Denticula nana Greg. Diat. of the Clyde p. 23. 

 T. II. F. 34.). D. minor, medio infiatum, apicibus dilatatum; valvis 

 ovalibus, polos versus subito attenuatis ; striis 24 — 30 in 0,001". v. s. 



Long. variat: l /i*i— tyiH*' = 0,00048—0,00073". 



Hab. ad oras Scotiae (Gregory), Hiberniae, in arena litorali maris 

 Adriatici (Lorenz), in limo maritimo maris mediterranei „Cap Martin" 

 (Bottcher) ; in algis marinis „Cap S. Andrea" prope Genuam (Piccone). 



D. distans Pritch. (1. 1. T. IV. F. 34. Denticula distans Greg. 

 1. 1. F. 36.). D. major, robustum, valvis late lanceolatis, apicibus 

 obtuso - rotundatis ; striis validissimis, brevissimis, remotis, 10 in 0,001", 

 areu late lanceolata, percursa laevissima. v. s. 



Long. 1/50— V'32"' = 0,00177—0,00275". . 



Hab. ad oras Scotiae, in Tago salso, in arena litorali maris Adriatici 

 (Lorenz), adVenetiam, in algismajoribus ex portu Plymouth (herbar. Suhr). 



