GOMPHONEMA. 27 1 



capitate, triangular, obtuse, apiculate. Raphe surrounded by a distinct hyaline 

 zone. Median striae opposite the unilateral dot very shortened, the others 

 quite equally prolonged, finely punctate, radiate, 10 to n in i c.d.m. Length, 

 about 3 to 7 c.d.m. 



Fresh water. Rather common everywhere. 



var. coronatum. (G coronalum Ehr\ H.V.H. Atl., pi. 23, f. 15* ; 

 in Type No. 220), plate 7, fig. 300. 



More elongate (7 to 8 c.d.m.), broader and much more constricted 

 at the upper portion. 



Fresh water. Slightly rarer than the preceding. 



G. Augur Ehr. (Abh., 1840, p. 17 ; H.V.H. Atl., pi. 23, f. 29* ; Type 

 No. 208), plate 7, fig. 301. 



Valve cordate-cuneate, with upper apex obtuse-apiculate, lower apex 

 preceptibly attenuate, slighty subrostrate. Raphe with a distinct hyaline zone. 

 Median striae opposite the nodule very shortened, the others equally pro- 

 longed, radiate up to the apices, about 10 in t c.d.m. Length, 3 to 5 c.d.m. 



Fresh water. Rather frequent throughout. 



var. Gautieri. H.V.H. (H.V.H. Atl., pi. 23, f. 28*), plate 7, 

 fig. 302. 



Average size much larger (about 5 c.d.m.). Valve broader, margins of 

 upper portion of the valve nearly parallel, very slightly constricted. 



Rare. Louvain Gautier) 



CC. UPPER APEX NOT APICULATE. 



G. Subtile Ehr. (Verb, p. 128, No. 115; H.V.H. Atl., pi. 23, f. 13- 

 14*), plate 29, fig. 811. 



Exactly the same (with the exception of the upper apiculation, which is 

 absent), as G. acuminatum, of which it appears to be a miniature. Transverse 

 striae radiate, 10 in 1 c.d.m. Length, about 4*5 c.d.m. 



Fresh water. England (Norman), Lough Mourne, Ireland (Greg,) Elgin, Scotland (W. Arnott !) 



G. montanum Schumann. (Hoh. Tatra, p. 67, pi. 3, f. 35^ ; 



H.V.H. Atl., pi. 23, f. ^^ and 36* ; in Types Nos. 196 and 348), plate 7, fig. 

 303- 



Valve sometimes scarcely cuneate, more or less tri-undulate, with apices 

 very gently narrow, produced. Raphe with rather broad hyaline zone. 



