JOURNAL OF MICROSCOPICAL SCIENCE. 
EXPLANATION OF PLATES XXXII & XXXIII, 
Illustrating Dr. A. A. W. Hubrecht^s Memoir on “ The Pe- 
ripheral Nervous System in Palaeo- and Schizonemer- 
tini, one of the Layers of the Body-wall.^’ 
Fig. 1. — Diagram of a transverse section of Carinella. The longitudinal 
nerve-trunks and the nervous sheath (indicated by red) are wholly outside 
the muscular body-walh into which processes are being sent out by the 
the sheath. 
Fig. 2. — The same of one of the Schizonemertini. The nervous tissue 
is enclosed within the muscles of the body-wall. 
Fig. 3. — The same of one of the Hoplonemertini. The longitudinal 
trunks lie inside the muscular body-wall. The nervous sheath has dis- 
appeared, and is replaced by metameric branches placed at regular intervals 
and double, one being for the dorsal, the other for the ventral half. These 
branches divide dichotomously. 
Fig. 4. — Part of a transverse section of Carinella annulata in the pos- 
terior half of the body. m. The longitudinal muscles of the body-wall, to 
which a thin layer [m) of circular muscles is exteriorly applied, b. Basal 
membrane of the skin. e. The deep cellular layers of the ectoderm, with 
glandular cells {c. c). n. The longitudinal nerve-trunk, with the inferior 
coating of ganglion-cells {nc.) applied to it, which gradually pass into the 
nervous sheath {nl.), the latter sending out processes {np.) into the muscular 
body- wall. In this figure the numerous radial fibres traversing the 
basal membrane (b) have been purposely omitted. Drawn with immersion 
vii, Seibert Krafft. 
PiQ, 5 . — Part of a longitudinal section through the region of the nervous 
sheath in Carinella polymorpha. Letters as in fig. 4. The processes («/?.) 
lead toward the cells of the ectoderm, not indicated in the figure. The 
nervous sheath appears more split up by fibrous and muscular tissue than 
in the foregoing transverse section. 
Fig. 6. — Transverse section through the lateral longitudinal marrow- 
trunk in Cerebratulus roseus. l, m. Longitudinal muscular layer, c. m. 
Circular muscular layer, separated from the former by a layer of a homo- 
geneous structure (like the basement membrane of the skin), through 
which, as through the muscular layers, pass numerous radial fibres. 
N. The lateral trunk situated in this homogeneous layer. Internally the 
fibrillar structure prevails, and this fibrillar nucleus is separated by a layer 
of connective tissue from the ganglion-cells {nc). Superiorly is represented 
a very large ganglion-cell, which was present in this section, though they 
