4o8 



GOMPHONITZSCHIA. 



N. (H.) subcohcerens Grun. (Diat Kasp, p. 23 ; h.v.h. Atl., pi. 



66, f. 14*), plate 35, fig. 915. 



Valves 3 c.d.m. in length, -4 in breadth; 9 or 10 carinal dots, and 33 or 

 34 transverse stria; in 1 c.d.m. Frustules living solitary or united in dense 

 fascicles (Grunovv). 



Marine. Leith, Scotland (Frauenfeld). 



N, (H.) sigmoidea, W. Sm., is nothing else but A T . fasciculate. 

 Grun., which we have previously described. 



Tryblionella, W. Sm. (figure 128) and Pritchardia Rab. 



(figure 129), are both true Nitzschia, as well as Perrya Kitton, 1877, 



(figure 130), which is distinguished by its carinal dots being prolonged into 

 long interrupted lines, so as to appear to form long rows of coarse dots. 



All the Perrya are exotic. The most remarkable species of this group 

 is the Perrya pulchcrrima {Grun. and Kitton), which will be found reproduced 

 on the preceding page. 



GENUS 82. -GOMPHONITZSCHIA GRUN., 1868. 



Frustules similar to those of Nitzschia, but 

 with cuneate valves and girdle face. The 

 frustules are sessile or stipitate, and in that 

 case they grow fiabilliform. 



Fig. 131. 

 Gomphonitzschia Ungeri. 



The Gomphonitzschia are, therefore, gomphonemoid Nitzschia. 

 The genus only includes two species, one G- Ungeri Grun. (fig. 131), 

 inhabits Egypt, and the other, G. Clevei Grun., has been found in Batavia. 



