Pig. 6. A highly magnified view of a segment of the preceding virgin uterus of
Orcella, and where the absence of utricular glands is still more apparent:
c,, connective tissue, submucous and free epithelial mucous layers, wherein
the fibrous tissue, fusiform corpuscles, and capillaries are well shown;
m., muscular and fibrovascular layers; s., serous coat.
„ 7. A piece in vertical section of the wall of the left cavity of the virgin uterus
of Orcella, and also demonstrating that no utricular glands are here
present: f , free mucous folds.
,, 8. A view of portion of the gravid uterus of Platanista close to the bare spots
and exhibiting in profusion the convolutions of utricular glands.
„ 9. A horizontal section of the vagina of the gravid P. ga/ngetica seen under an
inch object lens. I t illustrates the somewhat stellate appearance of the
here deeply situate mucous glands, described in the text.
„ 10. Specimen exhibiting a vertical section of the wall of the gravid horn of the
uterus of Orcella brevirostris, enlarged about 4 times natural size.
I t demonstrates the villous fcdded nature of the mucous surface, and in
the loose areolar tissue serpentine portions of many of the utricular
glands, and towards the lower muscular side the cut orifice of a large
blood-vessel.
„ 11. A highly magnified representation of portion of the above vertical section of
the gravid horn of 0. brevirostris: c. I. denotes the crypt layer; gl., the
glandular area, and at t. the transverse section of a utricular gland. The
epithilium lining the glands themselves is characteristically obvious.
„ 12. This corresponds to one of the 4 dark stellate spots of fig. 9 from the vagina
of a gravid female Platanista, but highly magnified. The figure is from
a horizontal section, as in fig. 9, and shows how the branches radiate from
the central receptacle.
PLATE XXXIX.
Pig. 1. Side view of an adult male skull of Platanista gangetica., reduced £
natural size.
„ 2. The female skull of an adult P. gangetica drawn to same scale: md., mandible;
mx., superior maxillary ; cr., its crest; pmx., premaxillary;/., frontal
; p., parietal; sq., squamosal; z., zygomatic process of squamosal;
o., orbit.
„ 3. A lateral view of the spinal column of Platanista from the atlas to last
lumbar vertebra: e., cervical; d., dorsal; I., lumbar region.
„ 4. The remainder of the same spine: cd., caudal vertebrae.
„ 5. Outer view of the sternum and costal cartilages of an adult specimen of
Plata/nista: p., prsestemum; a., angle; n., notch; f , facet for articulation
of second rib; on., mesostemum; z., ziphostemum; 3 third and 4 fourth
rib cartilages.
Pig. 6. Prsestemum of another specimen of Platanista showing variety m the
shape of the bone.
„ 7. Another variety in the figure of the first sternal piece of the Gangetic
Dolphin and belonging to a young animal.
PLATE XL.
Tabular view of the separated cranial bones of a mature foetus of Platanista
gangetica, all drawn of natural size.
Pig. 1. The frontal bone looked at from behind and within, i. e., its cerebral
surface: op., minute optic foramen of left side; fe., the back of the
exterior frontal expansion of the bone; and vo., projecting vomerine
spine.
„ 2. Supra-occipital, inside view showing (c.) median crest with lateral cerebral
concavities (whereon the latter is placed) and below the cerebellar fossa
With (cJ.) cleft or fissure reaching the foramen magnum.
„ 3. Posterior external surface of the right ex-occipital: c., condyle; «/•> jugular
space.
„ 4. An inside view of the left ex-occipital bone, (y.) being the jugular vacuity,
the lateral sinus lying alongside.
„ 5. The inner surface of the basi-occipital, {fin.) resting at the edge of the
foramen magnum.
„ 6. Outer surface of the right parietal bone, {sq.) being the roughened surface
of the squamosal suture.
„ 7. Inner cerebral aspect of the left parietal; the vascular groove (g.) of the
arteria meningea media being well marked below.
„ 8. A view from below of the right temporal, or squamo-tympanic bones, (z.)
being the zygomatic process and {sph.) the sphenoidal process.
„ 9. Tipper surface of the same bone of the left side: sq. roughened squamous
sutural surface; ty., tympanic; pe., periotic; sph., sphenoidal sutural
surface; z., zygoma.
„ 10. Interior aspect of the right tympanic bulla, i.e., that applied to the periotic.
„ 11. The basisphenoid, its upper cerebral surface.
„ 12. The palatal; {n.) surface of bone forming the wall of the narial passage.
„ 13. Internal surface of left pterygoid: n., smooth surface forming wall of narial
passage; pn., osseous limit posteriorly of narial passage; sms., sphenomaxillary
sinus; p., palatine surface; bss., basisphenoid suture; op., orbital
process; bss., basisphenoidal surface.
„ 14. Right pterygoid, its external surface: p., palatine surface; mxp., maxillo-
palatine process; sts., spheno-temporal surface; op., orbital process; pn.,
bony limit posterior nares.