NERVOUS SYSTEM AND SENSE ORGANS OF AMIURUS. 449 
PLATE IV. 
Fias. 1, 2, 3, represent dissections of the fifth nerve of the right side from 
Fig. 
Fie. 
Fig. 
Fig 
Fig. 
the roof of the mouth, of which 1 is the most superficial (ventral), 
and 3 the deepest (most dorsal). To expose the 3rd and 6th nerves 
and the ramus buccalis, as seen in Fig. 2, it is necessary to cut the 
supero-lateral and infero-medial strand, turning forwards the 
nerves to which they give origin. In Fig. 3 the 3rd and 6th nerves 
have been removed to show the cutaneous branches of the Rr. add. 
mand. and buccalis, as well as the branches of the R. ciliaris and 
opthal. profundus. The dotted lines in Fig. 3 indicate the 
boundaries of the adductor mandibule, AM; levator arcus pala- 
tini, LAP; and dilatator operculi, DO. 
4,—Dissection of same nerves represented in Fig. 6 from dorsal surfaces. 
1. Branch of R. oph. prof. to middle line nose. 2, Along 
medial border nasal sac. 3. To nasal barblet. 4. Along outer 
border nasal sac. 5. To fat, &c., in front of eye under origin of 
lev. are. pal. 6. Is the chief branch of R. ciliaris. 7. The cut- 
aneous branch of R. bucealis. 8. Of R. add. mand., with which 
are connected the muscular branches for lev. are. pal. and dil. op. 
9. Branch for muscle of maxillary barblet. 10. For add. mandib. 
5.—Diagram of brachial plexus. 
NN}, N*, N3, N4, &c. Ist, 2nd, 3rd, 4th, spinal nerves, of which 
the first four enter into the formation of the brachial plexus, 
Description of branches in text. 
6.—Diagram of Rr. dorsales and ventrales of the spinal nerves. Two 
vertebrez are represented by dotted lines. 
Rmv. Branches for ventral musculature. 
Rmp. & s. Branches from plexus supplying the deep and super- 
ficial muscles of the anal tin. The infracarinales are supplied by 
branches similarly derived to those marked #.m.s. 
. 7.—The first 8 vertebrz from the latero-ventral aspect. 
ao points to the aortic canal opposite the point of junction of 
the 4th and 5th vertebre. o0.0., the oblique, c.o!, the cres- 
centic ossitications referred to in the text. TJv., the transverse 
processes or costiferous pedicles of the anterior vertebre. V., 
VI.. VIL, &c. Bodies of the fifth, sixth and seventh vertebre. 
8.—Longitudinal vertical section of adult near middle line. 
1., 11, III., &. Centra of Ist, 2nd, 3rd, vertebre. H.O., exoccipi- 
tal. 8.0O., basioccipital. S.O., supraoccipital spine. Sp, JI]. & 
IV. Neural spines of the 3rd and 4th vertebre. 1, 2, 3, 4, &c. 
Points of emergence of the Ist, 2nd, 3rd, &c., pairs of spinal 
nerves. ov., in the fovea sacculi; directly above it is the opening 
into the cavum sinus imparis, on the osseous roof of which 1 
stands. The black spot above BO indicates the apertura interna 
of the atrium sinus imparis. The membranous roof of the cavum 
being removed shows the stapes and claustrum in the position 
indicated in 8a to the right of the figure: 
Fies. 9, 10, 11, 12, 13, are horizontal sections through the cephalic end of a 
fish of 3-4 cm. in length, of which 9 is the most dorsal. 9 and 10 
are merely intended to show the relations of the claustral cartilages 
to the cartilaginous cranium and roof of the spinal canal. 
Fig. 11.—7z, M. trapezius. Sc., supraclavicle. T'sc., trans- 
verse process of supraclavicle. r4., transverse process ,of 4th 
vertebra. Sp., saccus paravertebralis. Asi., atrium sinus imparis. 
