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ROBERT SCHARFF. 
developed sensory organs, as well as the organisation of the 
nerve-cord, seem to lead to a different conclusion, and I hope 
these points may soon be definitely settled. 
EXPLANATION OF PLATE XIV, 
Illustrating Mr. Robert Scharffs paper “Oa the Skin and 
Nervous System of Priapulus and Halicryptus.” 
Fig. 1. Priapulus. — Longitudinal section of a spike on the proboscis. 
h. Hypodermis. ci. Inner layer of cuticula. ce. Outer layer of cuticula. 
m. Limiting membrane, sp. Hollow space underneath spike in communica- 
tion with body cavity. 
Fig. 2. Priapulus. — Longitudinal section of a spike on the body proper. 
h. Hypodermis. ci. Inner, ce. outer layer of cuticula. c. c. Club-shaped 
cells of the hypodermis bearing short hairs. 
Fig. 3 a. Halicryptus. — Longitudinal section of a spike on the body 
proper, h. Hypodermis. ce. Outer, ci. inner layer of cuticula. e. c. Ex- 
ternal modified hypodermic cells, p. c. Pear-shaped cells. i. c. Internal 
modified hypodermic cells, m. Limiting membrane. 1. h. Long hairs project- 
ing through membrane. 
Fig. 3 b. — Cross section below the limiting membrane. Letters same as 
above. 
Fig. 3 c. — Cross section of the upper portion of spike, showing it to be a 
tube containing hairs which seem to radiate outward. 
Fig. 4. Priapulus. — Posterior part of the body. A ventral view, showing 
nerve-cord (».), papillae ( p .), also the tail-appendage ( t .). 
Fig. 5. Priapulus. — Diagrammatic longitudinal section of part of a pa- 
pilla. c. Cuticle, h. Hypodermic cells, greatly elongated and ending above 
in a flask-shaped portion (y.) with an opening (o.). 
Fig. 6. Priapulus. — Cross section of nerve-cord in the body. c. Cuti- 
cula. h. Hypodermis. a. m. Annular muscles, f. Fibrous nerve-mass. g. c. 
Ganglionic cells, h. p. Processes of hypodermic cells, n. c. Scattered cells. 
Fig. 7. Priapulus. — Cross section of nerve-cord in the proboscis, c. 
Cuticula. h. Hypodermis. f. Mass of nerve-fibres, g. c. Ganglionic cells. 
m. External longitudinal muscles of the proboscis, g. c. Ganglionic cells. 
