RHABDONEMA. 



361 



Valves lanceolate, with apices smooth, pseudo-raphe well marked, furnished 

 with costae, 8 in 1 c.d.m., alternating with rows of rather robust beads. False 

 septa furnished with only a single very large opening. Girdle face showing 

 numerous false septa, the intervals between which are filled with transverse 

 costae (7 to 7-5 in 1 c.d.m.), between each of which are found two rows o( 

 very fine beads, alternating. Length, 4 to 6 c.d.m. 



Marine. Antwerp, in the Scheldt (Belleroche). England (Kitton, Comber, Norman, Stolt.). 

 Scotland (Arnott). Ireland (O'Meara). Norway. 



R. minutum Kutz. (Baa, pi. 21, f. ii., 4 ; h.v.h. Atl., pi. 54, 



f. 17-21* j Type No. 362), plate 12, fig. 488^. 



Valves broadly lanceolate, with apices attenuate, showing a pseudo-raphe 

 distinct and covered throughout its length with striae, 9 in 1 c.d.m., composed 

 of coarse beads. Septa furnished with a single very large opening. Girdle 

 face presenting a small number of false septa, appearing to alternate, and with 

 margins furnished with coarse beads, 9 in 1 c.d.m. Length, 1 to 5 c.d.m. 

 Breadth, 1-5 to 35 c.d.m. 



Marine. Blankenberghe (H.V.H. ). England (Kitton, Comber, Norman, Stolt., W. Sm., 

 Ralfs). Scotland (Hennedy). Ireland (O'Meara). All the coasts of the North Sea. 



_ J 



GENUS 72.-CLIMACOSIRA GRUN., 1862. 



The genus Climacosira only differs from Rhab- 

 doncma by the septa showing numerous openings more 

 or less irregularly scalariform. 



It includes but one species CI. mirifica Gr. (K/iab- 

 donema jninficum IF. Sm.) found up to the present time 

 living in Brazil, Honduras and Asia, and fossil in the Island 

 of Nankoori. Figure 1 1 2 represents one of the characteristic 

 septa. 



Fig. 112. 



Climacosira 

 mirifica. 



