AURICULA. 



267 



Adriatic. Since then various analogous forms have been found, and Prof. 

 Cleve has included in this genus Amphiprjra complexa and A. decipims. 



ANALYSIS OF SPECIES. 



Valve in the form of a boat, 20 to 22 strice in 1 c.d.m. Connecting zone 



without scattered coarse dots . . . . .A. decipiens. 



Valve reniforni. 



I Striae fine, 20 in 1 c.d.m. 

 Striae robust 8 in 1 c.d.m. 



. A. complexa. 

 . A. Amphitritis. 



A. decipiens (Grun.) {Amphoropsis decipiens Grun. in CI. and 

 M. Diat., No. 309; H.V.H. Atl., pi. 22 bis., f. 11*; Amphiprora plicata 

 Greg., Diat. of Clyde, p. 33, pi. 4, f. 57). 



Frustule rectangular, somewhat constricted at 

 the median portion ; line of juncture sinuous, 

 median area indistinct, striae 20 in 1 c.d.m. 

 Sutural zone divided, having about three divisions 

 in 1 c.d.m., broad on the dorsal face, narrower 

 on the ventral face, and having about 22 stria; 

 in 1 c.d.m. Length of frustule, 6 to n c.d.m. 

 Breadth, 5 c.d.m. 



F; g 57- 

 A mpkoropsis decipiens. 



Marine. Coasts of Scotland (Greg., etc.) ! 



A. COmplexa (Greg.) CI. {Amphiprora complexa Greg, in Diat. 

 of Clyde, p. 36, pi. 4, f. 62*), plate 29, fig. 807. 



Frustule subquadrangular, elongated, with median portion constricted. 

 Valves arcuate, raphe inflexed. Connecting zone having 5 or 6 cuneate 

 segments, semi-lunar, somewhat constricted at the median portion, finely 

 striated, striae somewhat radiant, 20 in 1 c.d.m., bordered with a row of beads 

 (about 8 in 1 c.d.m.) on the dorsal margin. Frustules : length, 9 to 12 

 c.d.m. ; breadth, about 7 c.d.m. 



Marine. Coasts of Scotland (Greg ). 



The two following species which Prof. Cleve records from Sweden may 

 perhaps also be found in the North Sea. 



A. insecta Grun. {A. mucronata H. L. Sm., Spec. Diat. Typ. 

 No. 38 ; Am. Q.M.J., 1878, p. 17, pi. 3, f. 9*), plate 29, fig. 808. 



