Balch.— Marine Mollusca. 
PL.VTE 1. 
Fig. 1. A part of the radula of Polycerella emertonii Veri-ill (from Bergh ’83). 
Fig. 2. Two rows of teeth from the radula of Polycerella clavenportii. oc. 3.X 
oil immersion T ^. 
Fig. 3. A small specimen of Polycerella davenportii creeping on a hydroid 
stem. The animal drawn from a specimen of li mm. 
Fig. 4. Polycerella davenportii , dorsal aspect, m. = month, o. p. — oral palps, 
rli. = rhinophore, d. pap. = dorsal pappilla, c = cardiac prominence. 
From a specimen of 3 mm. 
Fig. 5. Polycerella davenportii , posterior aspect, a. = arms, f. = foot. 
Fig. 6. Polycerella davenportii , enlarged outline of gills and cardiac promi¬ 
nence. g. m. = medial gill, g. r. = right gill, g. 1. = left gill, w. = 
web, r. a. = rudimentary anterior branch. 
Fig. 7. Polycerella davenportii, side view. From a specimen of 4 mm. 
Fig. 8. Shell of Assiminea modesta Lea. After camera sketch. X35. 
Fig. 9. Operculum of Assiminea modesta Lea, drawn by W. Howe, after a 
camera sketch. X35. 
Fig. 10. Assiminia modesta Lea. e. = eye-spots, ped. = peduncle (fused eye- 
stalks and tentacles?), b. m. = buccal mass. The figure fails to 
show the relative sizes of the eye spots. The lateral spot should be 
' the larger by one third. 
Fig. 11. One row of teeth from the radula of Assiminea modesta Lea. After a 
camera sketch, oc. 1 X obj.7. 
Fig. 12. Dorsal aspect of Corambella depressa. From a camera sketch of a 
formol specimen of 4 mm., oc. 1 Xob. 3. 
Fig. 13. Ventral aspect of Corambella depressa from a camera sketch of a 
specimen cleared in cedar oil, oc. 1 X obj. 3. m. — mouth, o. p. = 
oral palps, s. e. = sexual extrovert, f. gl. — foot glands (?), a. pap. = 
anal papilla, g. pi. = gill-plates, c. = cardiac vessel. 
Fig. 14. 1 Ventral aspect of Corambella depressa resting on under surface of a 
slide, from a camera sketch, oc. 1 X obj. 3. rh. = rhinaphore, rh. sh. 
= rhinophe sheath. 
Fig. 15. One row of teeth from the radula of Corambella depressa. After a 
camera sketch, oc. 1. X oil-immersion t l. 
1 Note. Opportunity for further observation since the plate was made has shown 
that this figure is not a successful representation of the living animal in its normal 
state. The notaeum is represented as too ample and much too convex, the rhinophores 
(which usually turn backward in a graceful sweep) as too stout, the foot in creeping 
extends behind the mantle, while the oral palps are turned slightly forward. Neither 
the characteristic vermiform lines of the notaeum nor a large irregularly trilobed 
blotch which often appears near the middle of the foot is shown. The general outline 
is usually either almost rectangular or broadest posteriorly and often very slightly 
emarginate there. 
