EXPLANATION OF FIGURES ON PLATE I. 
1. Unusual form of Strop hia copia. 
2. Jaw of Strophia pannosa; z, blunt tooth; x, thin edge. 
3. J aw of Strophia copia, usual form. 
4. J aw of Strophia nana. 
5. Left side of animal of Strophia pannosa; M, mantle; F, foot; R, 
rectum; am, end of intestine; A, abdomen. 
6. Right side of animal of Strophia pannosa; E, eye; p, flap to ven- 
tral opening; v, ventral opening; R, rectum; L L, lungs; F, foot. 
7. Alimentary canal of Strophia copia; 0, entrance to mouth; J, 
jaw; s, proventriculus; I, oesophagus; p, solvent glands; H, duct to same; 
i, termination of stomach and beginning of intestines; T, cylindrical or- 
gan of tongue; c, retractor muscle of same; oc, supporting muscle; F, foot. 
8. Interior of mouth, or proventriculus; s, walls; ct, tongue; T, en- 
trance to cylinder; I, oesophagus. 
9. Side view of above; o, gullet; J, jaw; s, walls; ct, tongue: t, cyl- 
inder; tt, same detached; d, teeth of same; c, retractor muscle; oc, large 
muscle. 
10. Reproductive organs of S. copia; ov, combined ovaries and 
testes; sd, spurm duct; w, oviduct: oov, more enlarged view of same; 
rv, spurm reservoir; m, accessory organ of same; oi, intromittent organ, 
im, retractor muscle, and to the left, is a more enlarged view of same; 
me, muscle. 
11. Muscular system; N, lower muscle; w, right upper muscle; 
Q, left; oc, stomach muscle; h, lower branch of same; hh, upper; c, ab- 
ductor muscle of cylindrical organ t; x, terminus of clinging muscles; 
other letters same as in No. 7. 
12. Terminus of tongue muscle; x, fascicles. 
13. Animal of Strophia pannosa; ss, shells; tt, tentacles; ep, eye 
peduncles; es, eye specks. 
CONTRIBUTIONS TO SCIENCE, VOL. I. 
