CONSPECTUS OF THE FAMILIES AND GENKKA. LT> 



,i 



A 

 ( 



f Valves without pervious costae, quite smooth, or 

 j j very finely striate ; often with fine median line ; 



frustules hyaline in f. v 7 



- Valves and frustules not as above 9 



Frustules with spines (bristles) at the angles in f. v.. 



Atllinia XLTII. 



(. Frustules without spines 8 



Septae (or vittae) in f. v., interrupted, alternate 



TESSELLA XLIV. 



Septae not interrupted STRIATELLA XLV. 



Frustules compound ; valves with a median line, and 

 generally blank ends ; costate or striate. Septae 

 in f. v. connected by transverse striae (latticed); 



} frustules cohering, forming a flat filament 



BHABDONEMA XLVI. 



Valves mostly hyaline, with a few pervious costae 

 (scalariforni); linear, orbicular, or inflated 



BlBLARIUM XLVII. 



FAMILY VIII. SURIRELLE^E. 



f Frustules compound ; valves broadly oval, unlike ; 

 one costate, the other sieve-like (cribrose), punc- 



I tate ; without nodules CAMPYLONEIS XLVIII. 



I Frustules not as above 1 



f Valves transversely undulate, undulations conspicu- 

 . ous in f. v. ; striate, and with a few transverse 



I shaded bands : CYMATOPLEURA XLIX. 



I Valves not as above 2 



f Frustules in f. v. showing a marginal row of short, 

 o j sub-capitate processes ; valves transversely costate 



j (scalariforni) Clavularin L. 



^ Frustules not as above 3 



Frustules bent in s. v., margins finely dotted, valves 

 striate, without median line, and with an unequally 



3. 



notched inflation at one end ; cohering in a stel- 



late manner ACTINELLA LI. 



[_ Frustules not as above 4 



f Frustules linear in f. v. ; arcuate, with rounded ends 

 in s. v. ; margins punctate ; valves finely striate, 

 without median line, terminal nodules on the con- 

 cave margin. Frustules cohering in a zigzag man- 

 ner, or in tables Desmogonium LII. 



L Frustules not as above - r 



3 



