62 



HARDWICKE'S SCIENCE-GOSSIP. 



[Maech 1, 1S70. 



Professor Ehrenberg and Herr Grunow as to the 

 generic position of this form ; it appears to me to 

 be an Achnauthidium, rather than an Achnanthes ; 

 an opinion in which Dr. Arnott concurred. Neither 

 can I admit its identity with Stauroneis inflata of 

 Kutzing. The conspicuous pearly granules are not 

 shown in his figures, nor mentioned in the text of 

 his " Bacillarien," or " Species Algarum." He could 

 scarcely overlook them, even taking into consider- 

 ation the inferiority of the instruments in use at the 

 time the above works were written. 



Fig:. 61. Achnanthes inflata. 

 a, Upper valve, b, Lower valve, c. Frustule. 



Achnanthes inflata. — Frustules stipitate? arcuate; 

 valves conspicuously inflated at the centre ; ends 



Fig-. 6-2. Gomphonitzschia Ungeriann, x 400. 



broadly !j rounded ; lower valve with median line 

 and pseudo-stauros reaching margin; upper valve 



Fig. 63. Gomphonitzschia Uwgeriana, x 400. 

 a, Side view of valve, b, Side view of frustule. c, Front 

 view of frustule. d, Frustules in .situ, stipitate. c, Frus- 

 tules in situ, sessile. 



with excentric median line ; pseudo-stauros absent ; 

 markings transverse rows of conspicuous pearl-like 



granules : recent. Norwich, New Hebrides, Tahiti 

 (fossil), in fossil deposit Java, and New Zealand 

 (fig. 61). 



Gomphonitzschia (n.g.), Grunow. — Frustules 

 nitzschioid, sessile or stipitate. 



5. GoniphonilzsckiaUngeriana.Grunow. — Frustules 

 small, narrow, linear, cuneate ; valves linear-lanceo- 

 late, cuneate ; apices rounded, marginal puncta 

 33 in 'OCT' ; striae transverse, very fine, GO in "001" 

 (figs. 62, 63). 



6. Navicula pacifica, Grunow (fig. 6-1). — No de- 

 scription is given of this form ; the larger valve is 

 rhomboidal, apices acute, striae moniliform, distant, 



Fig. 64. Navicula pacifica. 



radiant, reaching median line; the smaller form is 

 elliptical, apices rounded ; in other respects like the 

 larger form. 



Herr Grunow notes the occurrence of Nitzschia 

 latestriata in the gatherings of the Novara, and in 

 doing so repeats the mistake of Prof. Smith and 

 Herr Kalfs. Nitzschia lilobata of the Synopsis is 

 not the Amphiprora latestriata of De Brebisson; 

 the latter form is not a Nitzschia but the Navicula 

 convexa of Smith, and the Scoliopletcra convexa of 



Fig. 65. Plettrostauron Frauenfeldianum, x 400. 



Grunow. M. de Brebisson, misled by the erro- 

 neous figure in the Synopsis, and which I believe 

 he saw before the text was printed, wrote to the 

 author that he thought it to be the same as his 

 A. latestriata. A comparison of the description of 

 the latter in the " Species Algarum " with that of A. 

 biloOata in the Synopsis at ouce shows that the forms 

 are not identical. Kutzing describes the striae as 

 coarse. Smith says those of N. bilohata are distinct, 

 56 in '001" (his figure represents them about 12 in 

 '001"). The practice of retaining the generic or 



