764 



SYSTEMATIC HISTOllY OF THE INFUSOEIA. 



nations), E., K., Sm. ; E. heptodon, 

 E., K. ; E. ododon, E., K. ; E. ennaodon, 

 E., K. ; E. decaodon, E., K. ; E. Jien- 

 decaodon, E., K. ; E. dodecaodon, E., K. ; 

 E. serrulcda (13 crenatious), E,, K. ; E. 

 jvmiotis (14 crenations), E., K. ; E. 

 2)oli/odon (all forms with more than 20 

 crenations), E., K. Fossil and recent. 

 Europe and America. — Breb., Rab., and 

 Kiitz. place E. tetraodon in Himanti- 

 diuni because the frustules are occa- 

 sionally united into short tablets. We 

 are unable to concur with them. 



¥^.Eleplias{E.). — Valves stout, curved, 

 with three dorsal teeth and broadly 

 rounded ends. EA. p. 126, t. 1. 4. f. 5. 

 Brazil. 



E. dizyga (E.). — Valves striated (?), 

 semilunate ; dorsum with four teeth, ap- 

 proximate at the middle. EA. p. 126, 

 t. 2. 1. f. 8. Cayenne. 



E. Corona (Rab.). — ^Valves nearly as 

 broad as long ; dorsmn tm-gid, with five 

 ridges ; venter shorter, and separated 

 from dorsum by a constriction. Rab 

 Diat. p. 17, 1. 1. f. 36. Italy. Striae di- 

 stinct, radiant. 



E. tridentida (E.). — Small ; valves 

 finely striated, curved, narrow-linear, 

 wdth three slight dorsal crenations, and 

 obtuse recm-ved apices. EA. p. 126, 

 t. 2. 1. f. 14 ; Grev Annals, 2nd series, 

 XV. pi. 9. f. 2. Europe, Asia, Africa, 

 and America. — We would unite this with 

 the following thirteen species imder the 

 name of E. Ehrenherf/ii. The valves are 

 linear, curved, with small dorsal teeth 

 or crenations, and become larger and 

 longer in proportion to the number of 

 their teeth. The striae are less radiant 

 than in E. robusta, and the dorsum less 

 turgid. 



E. qucdernana, EA. ; E. quinaria 

 (xii. 39), EA. ; E. senaria, E. septena, 

 EA. = E. scjitenaria, EM. ; E. octonaria, 

 E. 7ionana, E. denaria, E. undenaria, E. 

 Terra (12 crenations), E. trkkmaria, 

 E. quatuordenaria, E. quindenaria, E. 

 hioctonaria. Recent and fossil. Eu- 

 rope, Asia, Africa, and America. Ehr., 

 Kiitz. 



E. scalaris (E., K.). — Dorsum with 17 

 dorsal teeth. EM. pi. 17. 1. f. 44. Fossil. 

 Finland. In this and the two following 

 species Ehrenberg probably included 

 forms belonging to E. robusta and E. 

 Ehrenbergii. 



E. icosodon (E., K.). — Valves striated, 

 linear, curved, with 20 dorsal teeth. 

 ERBA. 1845, p. 77 ; Microg. pi. 33. 10. 

 f. 3. Fossil. America. 



E. polyodon (E.) resembles E. icoso- 



don, but has more than 20 dorsal teeth. 

 E. /. c. p. 77 ; Microg. pi. 17. 1. f. 45. 

 Fossil. Finland. 



Doubtful and insufficiently known Species. 



E. triglyphis (E.) = E. triodon, Ralfs, 

 Annals, vol. xiii. pi. 14. f. 3 ? Africa and 

 America. Sussex ? 



E. tetraylyphis (E.). Asia, Africa, and 

 America. 



E. pentaglpphis, EM. pi. 16. 2. f. 22, 

 & pi. 17. 1. f. 32. Europe, Asia, and 

 America. Valves minute, linear, with 

 five dorsal, approximate teeth, (iv, 3.) 



E. hexaglyphis, EM. pi. 16. 1. f. 34, 

 & pi. 16. 2. f. 24. Europe and Asia. 

 Resembles E. pentaglypliis, but has six 

 dorsal teeth. 



The above fomis are probably only 

 varieties. They seem to dift'er from E. 

 Ehrenbergii in more minute size, obso- 

 lete or indistinct striae, and approximate 

 teeth. 



E. Amphidicranon (E.). — Valve qua- 

 drangular, straight, transversely striated, 

 with constricted middle and emarginate 

 ends. ERBA. 1845, p. 77 ; Microg. 

 t. 33. 12. f. 14.^ Fossil. Oregon. 



E. brericornis (E.). — Oblong, dilated 

 with suddenly acutely rostrate ends ; 

 venter slightly concave at the middle ; 

 dorsum slightlv convex, nearlv smooth 

 (very finely striated?). ERBA. 1845, 

 p. 363. Marine. lndi?t. = A. Nitzschia? 



E. Cretcs (E.). — Valves striated, nar- 

 row-lanceolate, acute, very gradually at- 

 tenuated at each end. ERBA. 1844, 

 p. 81 ; EM. pi. 22. f. 55, 56. Cocconema 

 Oretce, E. Fossil. Sicily. 



E. Pileus (E.). — Small, striated, sub- 

 quadrate ; venter wider than dorsum, 

 the latter slightly furrowed ; ends ob- 

 tuse, rather prolonged. EM. pi. 39. 3. 

 f. 42. Siberia, Africa, and America. 



E. Gangetica, EM. pi. 35 a. 9. £ 2. 

 India. Fragments large, striated, mth 

 straight venter, convex dorsum, and 

 broadly trimcate apices, which are 

 slightly produced dorsally. 



E. Australis ; E. ceelata ; E. Cygmis ; 

 E. Paradoxa; E. sejpcntina, Australia, 

 Ehr. 5 E.Phrygia; E.lepida; E.Mosis; 

 E. rostrata ; E. Uralensis ; E. apiculata ; 

 E. Siberica ; E. borealis ; E. Leptostoma ; 

 E. umbilicata, Asia, Ehr. ; E. suhulis ; 

 E. curva ; E. carinata, Africa, Ehr. ; E. 

 Araucaniee; E. edulis, America, Ehr.; 

 E. Januarii, Brazil, Ehr. ; E. Guiatiensis ; 

 E.Demcrnrcc; E.Pomeroni; E. Savanna; 

 E. synedra, Guiana, Ehr. ; E. Columbia 

 Columbia, Ehr. 



