Plate III. 



Fig. T. Modiola iiiodiolus L., young. 



a. A left valve from the inner side, x J/'- Iceland. 



b. The anterior end of the same valve, x 7. 



— 2. Modiola pliaseolina P h i 1 i p p i. 



a. A left valve from the inner side, x i. Iceland. 



b. The anterior end of the same valve, x 8. 



— 3. Idas argent ens Jeffreys. 



a. A left valve from the outer side, x 672- S. of Iceland, 975 fni. (Ingolf St. 67). 



b. A left valve from the outer side, without the hairy periostracum. x 12. 



c. A specimen from the upper side, x 12. 



d. Hinge of right valve, x 10. 



e. Hinge of the same, x 20. 



— 4. Modiola ria discors L. var. Iccvigafa Gra\\ 



a. A specimen from Spitzbergen. x i. 



b. Dorsal view of the same, x i. 



— 5. Modiolaria discors L,. var. snbstriaia Gray. 



a. A specimen from West Greenland, x i. 



b. Dorsal view of the same, x i. 



c. A 25art of the middle area to show its "smooth" (simply striated) surface, x 5. 



— 6. Adodiolaria discors L. 



a. A specimen from Denmark, x 2. 



b. Dorsal view of the same, x 2. 



— 7. Modiolaria corrugata St imp son. 



a. A specimen from Spitzbergen. x I'/j. 



b. A specimen from West Greenland (Fiskenaesset). x 172- 



c. Dorsal view of the same, x 172. 



d. A part of the middle area to show its shagreen-like wrinkled surface, x 5. 



— 8. Modiolaria faba (M filler) Fabricius. 



a. A specimen from West Greenland (Ritenbeuk). x i. 



b. Dorsal view of the same, x i. 



c. Interior of the right valve, x i. 



— 9. Cardiiivi fasciatum Montagu. 



a & b. A specimen of the short, strongly ventricose form, x i^/.. Faeroes, 20 — 30 fm. 

 c & d. A specimen of the somewhat elongated, not much tumid form, x 3. West Iceland 

 (0nundarfj6rdr), ca. 12 fm. 



e. A specimen with tubercles not only on the anterior and posterior area, but also on the 

 middle area, x 6. West Iceland ((jnundarfjordr), ca. 12 fm. 



f. That form which was confused by Morch with C. cdnlc L,. x 1-/3. Faeroes. 



g. The same half from in front, x 3. 

 h. The same half from behind, x 3. 



i. A specimen with an obliquely cordiform contour, x S'/j. Faeroes, 135 fm. 

 k. A specimen half from behind showing an intercostal sculpture in the form of a fine 

 pricking, x 5. West Iceland (Onundarfjordr), ca. 12 fm. 



— 10. Cardium ciliahiiii Fabricius. 



A very young specimen, x 1072- East Iceland (Bakkafjordr), 52 — 43 fm. 



— II. Cardium echinatum L. 



A very young specimen, x 1072. South Iceland, 17 — 23 fm. 



— 12. Cardium (Scrripcs) groeulandicum Chemnitz. 



a. A very young, strongly sculptured specimen, x 6. West Greenland (Godthaabs Fjord). 



b. A very young, comparatively smooth specimen, x 5. West Iceland (Onundarfjordr), 10 fm. 



