2 8o ACHNANTHES. 



A. parvula Kutz. Baa, p. 76, pi. 21, f. 5; h.v.h. Atl., pi. 26, 



f. 25, 26, 27, and 28* ; Type No. 233), plate 8, fig. 326. 



Valve elliptic-lanceolate, not constricted at the median portion, the upper 

 having 11-13 plainly punctated stria in 1 c.d.m., the lower with a rather broad 

 stauros ; raphe surrounded with a small hyaline zone having 14-16 punctated 

 striae in 1 c.d.m. Connecting zone striate and plicate as in the preceding. 

 Length, 1 to i - 5 c.d.m. 



Marine. Ostend (Westendorp, No. 795). England (Norman). Ireland (O'Meara). France 

 Br^bisson). 



A. coarctata Breb. (In w. sm, s.b.d., ii., p. 31, pi. 61, f. 379; 



H.V.H. Atl., pi. 26, f. 17, 18, 19, and 20* ; Type No. 230), plate 8, fig. 

 3^7- 



Valves linear elliptic, constricted "in the median portion, and slightly so 

 near the apices, which are sub-capitate, sub-truncate, rounded ; upper valve 

 with pseudo-raphe very eccentric, striae distinctly punctate, 12 to 14 in 1 

 c.d.m., appearing oblique from the median portion ; lower valve with a broad 

 stauros, having 13 to 15 striae in 1 c.d.m. Length, 1 to 4 c.d.m. 



Fresh water. Frahan (Delogne), England (Comber, Norman), Scotland (Baxter Coll., No. 2^79), 

 Ireland (O'Meara), France. 



aa. UPPER VALVE WITH RAPHE ECCENTRIC, STRAIGHT 



A. Hungarica Grun. (Arct. D., p. 20 , h.v.h. Atl., pi. 27, f. 1 

 and 2* ; in Type No. 196), plate 8, fig. 328. 



Valves linear lanceolate, with apices rounded-obtuse or cuneate ; upper 

 valve with striae almost parallel, the two median shortened ; lower valve with 

 radiant strise finely punctate, about 21 in 1 c.d.m. Raphe surrounded by a 

 narrow hyaline area, somewhat broader about the middle of the valve. 

 Length, 2 to 3 c.d.m. 



Fresh water. Antwerp, Austruweel, and Wilryck, near Antwerp (Gaut.). England ! 



A. affirm Grun. (Arct. D., p. 20 ; H.V.H. Atl., pi. 27, f. 39 and 

 40*), plate 8, fig. 329. 



Valve linear lanceolate, narrow, with apices obtuse rounded, having 27 to 

 30 striae in 1 c.d.m. tipper valve with almost parallel striae ; lower valve with 

 radiant striae and broad pseudo-stauros. Length, 1*5 to 2-3 c.d.m. 



Fresh water. Btussels (Delogne.) 



