HANT2SCHIA. $&l 



ANALYSIS OF SPECIES. 



f Carinal dots prolonged into costte, which traverse the entire valve . H. marina. 



Carinal dots ( Carinal dots slightly prolonged . . H. virgata. 



slightly or not < 



prolonged. ( Carinal dots not prolonged . . . H. amphioxys. 



H. amphioxys (Ehr. ) Grun. (Arct. Diat, p. 103; Nitzschia 



amphioxys, IV. Sm., S.B.D., L, p. 41. pi. 13, f. 105 ; H.V. H. Atl., pi. 56, f. 1 

 and 2*; Type No. 367), plate 15, fig. 483/'. 



Valves feebly arcuate, with apices more or less prolonged. Keel with 

 coarse short dots, about 7 in 1 c.d.m., the two median distant. Striae about 

 16 in 1 c.d.m. Length (very variable), about 4*5 or 7-5 c.d.m. 

 Fresh and brackish water Frequent. England (Kitton, W. Sm., Norman). Ireland (O'Meara). 



var. major. (H.V.H. Atl., pi. 56, f. 3 and 11*), plate 15, fig. 484/'. 



Much larger, about 12 c.d.m., with 5 to 6 carinal dots, and about 11 

 striae in 1 c.d.m. 



var. intermedia. (H.V.H. At!., pi. 56, f. 4*), plate 15. fig. 485/;. 



Pfean length, about 8 c.d.m., with 4 carinal dots, and about 11 striae 

 in 1 c.d.m. 



var. vivax. (Nifzschi'i vivax Hanizscli non IV. Sm. ; H.V.H. Atl., 

 pi. 56, f. 5 and 6*; Type No. 368), plate 15, fig. 486/;. 



Valve slender, longly rostrate ; about 5 carinal dots and 13 striae in 1 

 c.d.m. Length, 10 c.d.m. 



Brackish water. England (Kitton). 



var. elongata. (H.V.H. Atl., pi. 56, f. 7 and 8*), plate 15, fig. 487/-. 



Length, up to 22 c.d.m.; strongly rostrate and genufiexed ; 7 or 8 

 carinal dots, and 17 striae in 1 c.d.m. 



H. virgata (Roper) Grun.! (Arct. D., p. 104; H.V.H. Atl., 



pi. 56, f. 12 and 1 3* ; Type No. 370), plate 15, fig. 488/'. 



Valve robust, arcuate, with apices strongly rostrate, rostrum obtuse > 

 Keel with 4 or 5 dots in 1 c.d.m., dots prolonged into short costae on the 

 valve. Striae, 9 to 11 in 1 c.d.m. Length, about 13 c.d.m. 



Marine. Blankenbcrghe (H.V.H.), washings of mussels (Deby.), France (Breb.), England 

 (Roper, Kitton, Comber, Stolt, Norman), Ireland (O'Meara). 



