OF THE STEIATELLE.li;. 



807 



Bihlarium elegans, EM. t. 33. 2. 

 Fossil. Siberia. Elirenberg's figure of 

 tliis species differs from T. Rhombus 

 merely in its more developed inflation. 



T, ithomhm (E.). — Lateral view rhom- 

 boid, with subacute angles. = Bihlarium 

 Rhombus, EM. pi. 33. Fossil. Siberia 



f. 4. and Oregon, 



T. ? Crux (E.). — Lateral view cruci- 

 form, with transverse parallel strice and 

 a median &\it\\YQ. = Bihlarium Crux, EM. 

 pi. 33. 2. f. 3. Siberia. Strije 18 in 

 1-1152". A doubtful member of this 

 genus. 



Genus TABELLAEIA (E.). — Frustules quadrangular, united into a fila- 

 ment, at length partially separating and forming a zigzag chain ; septa equal, 

 straight ; lateral surfaces inflated at ends and middle. Aquatic. Tabellaria 

 differs from the other genera of this family by having three inflations of the 

 latei^ surfaces. 



Tabellaria Jlocculosa (Roth, K.), — i 

 Joints subquadrate, with from 3 to 7 ! 

 attenuate septa from each margin ; la- ; 

 teral view with three nearly equal infla- | 

 tions ; the intennediate portions linear. | 

 SBD. ii. p. 4o, pi. 43. f. ^IQ.^Bacillaria ' 

 taheUaris, EI. p. WlQ.=Navicula trinoclis 

 in part, E. = Tabellaria vulgaris^ E. Com- 

 mon, (xin. 29.) Best distinguished 

 from T. fenestrata by its less elongated 

 frustules and more numerous septa, 

 which usually alternate with those fi'om 

 the other margin. We believe, however, 

 that each complete septum has an oppo- 

 site one which is generally rudimentary, 

 though sometimes more developed and 

 conspicuous. 1-860" to 1-480". 



T. ^•ew^mosa (K.). — Frustules as in 

 T. Jlocculosa, but the central inflation of 

 the lateral view much larger than the 

 terminal ones. ItB. t. 30. f. 74. = T. bi- 

 ceps, EM. several figm-es. (xiii. 26.) 

 Common. 1-960". Professor Smith 

 unites this to T. Jlocculosa, and, as we 

 believe, justly, since intermediate forms 

 are not uncommon, 



T. Gastrum (E.). — Very small ; lateral 

 view with a subglobose median inflation 

 and somewhat narrower capitate apices. 

 KSA. p. 119. Fossil. Labrador. 



T. robusta (E.). — Thick, three times 

 as long as broad, with broad gibbous 

 .centre and large subacute terminal 

 capitula. EM. pi. 33. f. 15. Fossil. 

 America. 1-864". Probably another 

 variety of T. Jlocculosa. 



T. amphilepta, EM. pi. 3. 4. f.32. Fossil. 

 Boston, Ehrenberg's figure shows the 

 lateral view with inflated centre, as in 

 T. Jlocculosa ', but the extremities are not 

 dilated. 



T. twclosa (E.). — Small, slender, no- 

 dose ; nodules five, the median one rather 

 largest, those adjoining oblong. EM. 

 several figures. Siberia. Lough Momiie 

 deposit, &c. Ehrenberg's figm-es are 

 elongated, with four constrictions, and 

 consequently five inflations, of which the 

 median and terminal are suborbicular 

 and the intermediate oblong. '^ Akin to 

 Grammatophora undulata " (E.). 



T. fenestrata (L^TQg., K.). — Front view 

 linear, with two opposite septa from each 

 end ; lateral view wdth three nearl}^ equal 

 inflations and linear connectino^ portions. 

 KB. t. 17. f. 22. = Tahellarm trinodis, 

 EM. many figm-es. Common. 1-600" 

 to 1-280", 



Species doubtful, or known to us only by 

 name. 



T. amphicephala (E.). — Very small, 

 with strongly inflated centre and capi- 

 tate apices. KSxA.. p. 119. Fossil. San 

 Fiore. 1-1728". Scarcely distinct from 

 T. ventricosa. 



T. p>laty stoma (E.), Sandwich Islands ; 

 T. rhabdosoma (E.), Asia ; T. pinmdaria 

 (E.), Asia; T, clavata (E.), Northern 

 Asia; T. undulata (E.), Northern Asia; 

 T. eurocephala (E.), Persia; T. Semen 

 (E.), India; T. Bacillum (E.). 



Genus GEAStOIATOPHORA (E.),— Frustules forming a filament, at length 

 partially separating and becoming a zigzag chain ; septa in pairs, opposite, 

 generally curved; lateral view oblong-lanceolate, not inflated. Gramma- 

 tophora is easily distinguished from all the other genera by its strise having 

 commonly a cui've outwards near the base ; and when this curve is wanting 

 it may be known from Tabellaria by the absence of inflation. Although 

 Kiitzing describes several species of this genus as smooth, yet Tve believe that 

 all the species are striated; and notwithstanding we have admitted this 



