Naviculacea.] iNFrsoRiAT, antmalcules. 325 



Bihlarium is intoitnediate betwcon Tessella and Tahellaria ; it 

 approaclics Striatella, but differs from that genus by the absence of a 

 pedicle. 



All the species hitherto met with are fossil. Ehrenberg siipposea 

 them, fi-om their geological position and I'elations, to have been in- 

 habitants of brackish water. 



The above characters are gathered from a report on a paper by 

 Ehrenberg, read before the Berlin Academy. 



BiBLAEiTJM Glans = Navieula (?) Glans. — Laterally valves oblong, 

 tumid at the centre, apices obtuse ; with loose parallel striae, seven ta 

 eight in 1- 720th, or four to six in 1 -1440th. No suture visible. 

 Length 1 -480th. Finland, Siberia, and Oregon. 



B. (?) gihhim. — Smooth, bacillar ; two, three, or foiu' concatenated; 

 straight at the centre ; laterally, gibbous at the centre. No central 

 aperture observable. Length 1-11 52nd. Kurdistan. 



B. compressum. — Laterally narrowly elliptic ; lanceolate, obtuse, 

 with loose, transverse, parallel pinnae, interrupted by no median 

 suture, and five to seven in 1-1 152nd. Length 1 -648th. Oregon. 



B. castelliim. — Ovate, obtuse ; with four marginal sinuses on each 

 side. Lateral valves not observed. Length 1 -900th. Siberia. 



B. (?) Crux = Navieula crux. — Lateral valves quadrangular^ 

 striated ; deeply and unequally angular, so as to resemble the figure 

 of a cross; with transverse parallel striae, interrupted by a median 

 suture; eighteen in 1-1 152nd. Length 1440th to l-864th. Fossil, 

 Hesse Cassel; living and fossil in Siberia. 



B. ellipticiim. — Lateral valves elliptical, striated transversely; with- 

 out a suture. Stiiae five to eight in 1-1 152nd. Length 1 -1080th. 

 Siberia and Oregon. 



B. emarginatum. — Lateral valves quadrangular, unequally and 

 deeply angular, assuming a crucial form, with two opposite (ventral) 

 obtuse and emarginate rays ; transverse striae strong, but lax, seven 

 in l-1152ud. No suture. Length 1 -864th. Siberia and Mexico. 

 "I have seen nineteen leaflets concatenated, and two such collections 

 (Kbelli) also connected" (Klitz.) 



B. (?) Follh, of North America = Navieula (?) FoVis of Europe ; 

 but would perhaps be more rightly transferred to Tahellaria. — Lorica 

 depressed, swelled at the middle, without longitudinal striae. It i 



