Plate IV. 



Fie. i. Astarte boreal is Chemnitz. 



a. A specimen without folds and with an almost smooth periostracum. x i. West Iceland, 22 fin. 



1). The same from above. 



c. A very high form, with quite narrow folds on the uppermost part of the shell and with 



fairly thick, fibrous periostracum on the lowest part, x 1. West Iceland (Faxafjordr), 



8— n'\ fin. 

 il & e. A strongly compressed form with distinct folds on the uppermost part of the shell. 



x 1. West Greenland. 



f. A very elongated form from East Greenland (Hekla Havn). x i'/z- 



— 2. Astarte Montagui Dillwyn. 



a. Forma typica, a short and high, somewhat triangular form, x i l / 2 . West Iceland iFaxa- 

 fjordr), 15 — 16 fm. 



b. Var. striata (Leach) Sars, a more elongated form, x i 1 :,. West Greenland (Jakobshavn). 



c. Var. Warhami Hancock, an elongated, elliptical form, x 1. East Greenland (Hurry Inlet), 

 10 fm. 



— 3. Astarte sulcata da Costa. 



a X: 1). A typical specimen from the Faeroes, 150 fm. x 1. 



c. A specimen with comparatively close-placed ribs, from Denmark Strait off south-eastern 

 Greenland (Ingolf St. 94), 204 fm. x 1. 



— 4. Astarte elliptica Brown. 



a X: b. A typical specimen from the Faeroes (Klaksvig), 10 — 15 fm. x 1. 

 c & d. A very elongated form, from East Greenland (Hekla Havn). x 1. 

 e & f. A very high and convex form, from West Greenland, x 1. 



g. A specimen in which the folds disappear almost about the middle of the shell, x 1. West 

 Greenland (Vaigat). 



— 5. Astarte crenata Gray. 



a & b. A typical specimen from East Greenland (Hurry Inlet), 50 fm. x 1. 

 c. A specimen with fewer and more prominent ribs, x 1. East Greenland (Cape Hope), 121 fm. 

 d & e. A specimen of var. siibwqitilatera Sowerby. x 1. Davis Strait (Ingolf St. 32), 318 fm. 

 f & g. A specimen of var. erebricostata Mc. An dr. & Forbes, x 1. North Iceland (Skage- 



strands Bugt), 119 fm. 

 h & i. A specimen of var. inflata Hagg. x i 1 /,. East Greenland (Forsblads Fjord), 90 — 50 fm. 

 k & 1. A specimen of var. acuticostata Jeffreys, x i 1 ^. S. of Jan Mayen (Ingolf St. 116), 



371 fm. 

 111. A part of the shell, more magnified. 



