OF THE LIOMOPHORE.E. 



769 



Genus PODOSPHEXIA(E.).—Fmstiiles affixed, in front view cuneate, 

 in lateral view elavate, stipes none or obsolete. Podosphenia is identical with 

 Styllaria (Ag.). Its sessile frustules distinguish it from the rest of tho 

 Licmophorece, and the absence of transverse costa3 from the Meridieae. " This 

 genus represents in the Licmophorea) the genus Sphenella of the Gompho- 

 nemete ; for, like that, it is distinguished from other genera of the same family 

 by the more or less complete absence of the stipes. The obovate-lanceolate 

 figure of the secondary surfaces is precisely that of the Sphenellae and of the 

 Gomphonemeae in general. The cuneate form of the primary surfaces is, in 

 Podosphenia, always more dilated at the summit and acute at the base, so 

 that they resemble a triangle more than a trapezium." (M I. c. p. 462.) 



nia ahhreviata, E. ; P. Linghyei, SBD. 



PoDOSPHENiA^i7/-«a7/,s(E.). — Frustides 

 narrow cuneate, elongated, with some- 

 what acute base; lateral \dew elavate, 

 smooth or with verv obscure striae. KB. 

 t. 9. f 10. 1. Europe, (x. 186.) jS. mino)' 

 1-250" to 1-110". 



P. tenuis (K.). — Linear cuneate, elon- 

 gated, very slender, with acute base ; 

 lateral view narrow-clavate. KB. t. -30. 

 f. 51. Norway. 



P. 7iana (E.). — Small, smooth, narrow 

 linear cuneate ; lateral view elavate with- 

 out lines. EM. pL 11. f. 18, 19. Fossil. 

 Bilin, Bohemia^ 1-2300" to 1-1720". 



P. clehiUs (K.). — Smooth, narrowly 

 cuneate, rather acute at the base, sub- 

 flabellate. KB. t, 8. f. 7. Em-ope. 

 1-1380". 



P. tergesiina (K.). — Cuneate trian- 

 gular, geminate or ternate, conjoined in 

 a ilabeUate manner, base rather acute. 

 KB. t. 8. f. 13. Trieste. 1-1440". 



V.hyalina (K.), — Very hyaline, cu- 

 neate, with approximate \dttiie and sub- 

 acute base ; lateral view obovate pvri- 

 form. KB. t. 10. f. 2. /S. r«ce/;ws«,'K., 

 obsoletely stipitate, 1. 10. f. 3. Em'ope. 

 1-570" to 1-480". 



P. cuneata (Lyngb., Ag.). — Broadly 

 cuneate with rather acute base; lateral 

 view elavate or obovate, with obscure 

 striae. = Styllaria cuneata, Ag. ; Podosphe- 



Genus HHIPIDOPHOPA (K.). — Frustules stipitate, in front view cuneate, 

 in lateral view obovato -lanceolate ("^ith a median longitudinal line," S.). 

 " We encounter the same difficulty in distinguishing Ehipidophora from 

 Podosphenia that is experienced when practically applying the generic 

 distinction established between Sphenella and Gomphonema and in aU other 

 similar cases (Cymbella and Cocconema, &c.) ; these diifer only in the stipes, 

 which is very variable in length and not always entirely wanting in the first 

 of these two genera. 



" The large size of some among the species enumerated by Kiitzing permits 

 us to observe clearly the conformation of the shield. Let us suppose a 

 cylindrical articulation of Melosii'a, and so compress it unequally on one of 

 its sides, and in the direction of both pairs of opposite surfaces, that the 

 resulting form shall be cuneate, and the two incomplete diaphragms formed 

 by the internal prominence of the longitudinal canals shall extend like these 



3d 



Europe, (xm. 13 h.) 1-240". Stride 46 

 in -001", S. Broader and shorter than 

 P. gracilis. 



P. Jurgensii (Ag., K.). — Broadly cu- 

 neate with trmicate base ; lateral view 

 elavate, vnih. obscure striae. SBD. i. 

 p. 83, pi. 25. I 228. Europe. 1-432". 

 Strii© 48 in -001", S. 



P. ovata (S.). — Cuneate with rounded 

 angles ; lateral view obovate, tapering 

 into an acute base ; striae moniliform. 

 SBD. i. p. 83, pi. 24. f. 226. Shoreham 

 harbour. Stride 24 in -001". -0033" to 

 •0042", S. 



P. Ehrenhergii (K.). — Large, broadly 

 cuneate; lateral view tapering at both 

 ends and with distinct moniliform trans- 

 verse striae. SBD. pi. 24 £ 225. Eu- 

 rope, (iv. 7 ; XIII. 14.) 1-140". Striae 

 27 in -001", S. 



Doubtful Species. 

 P. Pupula, EM. Several figures. Ehr- 

 enberg's figm-es have a elavate lateral 

 valve with pervious transverse costae and 

 wdth or without a constriction. All pro- 

 bably belong to 3Ieridion circulare and 

 M. constrictum. He gives about twenty 

 stations for this species m different parts 

 of the globe, — none marine. 



