Explanation of Plate 18 



Fig. 1. — Yoldia myalis (Couthouy) from 118 feet. 



Fig. 2. — Nuculana radiaia (Krause) from 80 feet (Aug. 21, 1948). 



Fig. 3. — Nuculana minuta (Fabricius) from 522 feet. 



Fig. 4. — Nucula tenuis Montagu from 118 feet. 



Fig. 5. — Yoldia hyperhorea Torrell ex Loven from 132 feet. 



Fig. 6. — Musculus niger (Gray) from 204 feet. 



Fig. 7. — Musculus corrugatus (Stimpson) from 175 feet. 



Fig. 8.~Yoldia arctica (Gray) from 28 feet (Aug. 4, 1948). 



Fig. 9. — Thracia {Lampeia) adamsi, new subgenus, new species, from 110 feet (Sept. 15, 



1948). 

 Fig. 10. — Musculus discors var. laevigatus Gra\" from 40 feet (Eluiikak Pass, Aug. 1, 1950). 

 Magnification: All X 1-56. 



