115 



D. Inoeolatfc, utroquc fine obtusa, costis 10 — 14 in 0,001", latcrc ob- 

 longo-lincaris, utroquc fine obtuBO-iotundata, msrgine punotato - ocellata. 



Long. prioris. Spccimina gallica ad ' »*" = 0,0018" longa. 



Hab. in thermis Italiae, Hungariae, Galliae: Puy-de-D6me. For- 

 mam minoivm in stagnis pxope St. Veit Austriae ol.scrvavit cl. Grunow. 



D. subtilis Grim. (in Wicn. Verh. 1862. p. 547. T. XII. F. 86.). 

 D. minuta, lineari-laneeolata, subacutata; costis 18 — 20 in 0,001", 

 stiiis inti rstitialibus ultra 40 in 0,001"; laterc angustc linearis. n. v. 



Long. 0,0005—0,0010, lat. valvarum 0,00012—0,00015". 



Ilab. in aqua subsalsa ad litora Angliae. 



D. crassula Kiigeli (in Ktz. Spec. Alg. p. 889. 1849 ! Dent. inflata 

 Sm. Diat. II. p. 20. T. XXXIV. F. 294. Pritch. Inf. p. 773.). D. parva, 

 late elliptica, costis 12 in 0,001", striis 37—40 in 0,001"; latere ob- 

 longa, utroque fine truncata, obtusangula, margine punctata. v. v. 



Long. Vigo— V$-"' = 0,00055—0,00102". 



Hab. in aquis dulcibus Angliae : Beachey Head, Sussex (W. Smith), 

 Lincoln (Carrington) ; Galliae : prope Falaise (De Brebisson) , Chateau 

 d'Eau , Montpellier , Xismes (W. Smith) , Thouare , Lambersart prope 

 Lille (DesmaziOres) ; Sardiniae: Vercelli (Cesati), Mentone (Boettcher) ; 

 Helvetiae (Xaegeli), Borussiae (Schumann). 



D. elegans Ktz. (Bac. 1. 1. F. 5. Kabenh. Siissw. Diat. 1. 1. F. 5. 

 Alg. X. 1081. Wartm. X. 126. Pritch. Inf. p. 773. T. III. F. 4. 

 D. ocellata Sm. Diat. I. p. 22.). D. mediocris, lineari-elliptica, apici- 

 bus obtusis, costis 9 — 11 in 0,001", latere oblonga, utroque polo late 

 rotundata, marginc punctato-ocellata v. v. 



Long. V'62— 74s"' = 0,0014—0,0018". 



b. Forma minor, l /»4 — V 80 '" longa, costis 7 — 9 in Vioo'". Wartm. 1. 1. 



Hab. in aquis fluentibus et stagnantibus, nec non ad rupes humec- 

 tas per Germaniam, Helvetiam ; porro ad arcem „Korb" Tyrolis au- 

 stralis (v. Heufler) ; in Anglia : prope St. Abb's Head (Balfour). 

 b. D. costis alternis marginem versus subliteratis. 



D. obtusa Sm. (Diat. 1. 1. F. 292. non Ktz. Rabenh. Siissw. 

 Diat. 1.1. F. 8. Alg. X. 985. D. Kiitzingii Grun. in Wien. Verh. 1862. 

 p. 548. T. XII. F. 15.). D. lanceolata, apicibus obtusis vel acutius- 

 culis, costis in 0,001" 12—20, striis in 0,001" 36—40; latere linearis, 

 utroque polo truncata, costis marginalibus brevissimis. v. v. 



Long. 7i«o— Vw = 0,0005—0,0029". 



Hab. in aquis dulcibus pcx totam Europam passim. 

 Sp eeies f ossiles. 



D. lauta Bail. Micr. Organism. T. IX. F. 1 et 2. — California. 



