210 MR. W. K. PARKER ON THE STRUCTURE AND 
organs (j.0.) and the perfect part of the cartilage. The roof (al.sp.) is now arched, 
with a very small median groove; this roof is very thick for some distance, and 
then thins out below, where it is bulbous. The upper three-fifths of the septum 
(s.n.) is of the same thickness as the main part of the roof, and then suddenly 
swells into a large bulb, witha flattened basal outline. Here the cartilaginous capsules 
of JAcOBSON’s organs (7c.c.,) are at their perfect part. They are solid above, 
and nearly vertical where they fit obliquely to the septal base; then they curve 
outwards to form an oval cavity (for JAcoBsoN’s organ, j.0.), and are keeled and turned 
inwards below. In the middle of the pyriform space between them the thin palatine 
plate of the premaxillary is seen to rest obliquely on the top of the inner face of the 
tubular part. The nasal passage opens into the palatal space below; the nasals 
(n.) are cut through above, and the fore part of the maxillaries (m.) with a 
tooth and its pulp (f.) on each side. Three mucous follicles (m.s.) are seen in the 
interspace between the mucous membrane and the aliseptal cartilage. This part is 
close behind the anterior palatine foramina, and here the palate is rugous and sub- 
carinate in the middle. 
Section 8.—This (Plate 30, fig. 8) is through the open part of the recurrent 
cartilages (re.c.) and the hind part of the palatine processes of the premaxillaries. 
The thick aliseptal wall has now formed a definite rudiment of the nasal turbinal 
(v.tb.), but the rudiment of the inferior turbinal (7.tb.)* is still very imperfect. The 
nasals were present, but not figured, and part of the maxillaries (m.x), with a pulp, 
are cut across and the fore part of the vomer (v.). Also, below, the dentaries and 
their teeth-pulps (d.) are seen. 
Section 9.—Here (Plate 30, fig. 9) the vomer (v.) comes fully into view behind 
the palatine processes of the premaxillaries (see Plate 29, figs. 1, 2, 4, 5). The 
nasals (n.), and the maxillaries (m.,), with their palatine plates ascending to articulate 
with the vomer, are all clearly seen. Also the dentaries (d.) below, with their teeth. 
Here the nasal and inferior turbinals (1.tb., 7.tb.) have good rudiments. The front 
of the tongue (tg.) and the lower jaw (d.) have been cut through, below. 
Section 10.—Here (Plate 30, fig. 10) the nasal labyrinth is widening towards 
the true olfactory region; the septum is deeper and less bulbous below. The 
inferior turbinal rudiment is no longer seen, but the nasal (2.¢b.) is still in view. 
The nasals, maxillaries, and dentaries (mz., d.) are still seen in section. 
This section is behind the angle of the mouth; the tongue (tg.) is now at its 
middle. 
Section 11.—Here (Plate 30, fig. 11) the eye-balls (e.) are cut through their front 
part, and the nasal labyrinth, largely osseous, is cut across where the nasal, upper, and 
middle turbinals (7.tb., «.tb., a.tb.), can all be seen; the floor is ossified at this 
part. The nasals, vomer, maxillaries, and palatines (n., ma., pa.) are here cut 
through, and the dentaries (d.) below. In the last (fig. 10) the nasal passages 
* The line in the figure is carried too low. 
