XEROPHILA VIRGATA. 145 
intense black, was thus limited to the muzzle and to the dorsal and sub-dorsal 
areas ; the DORSAL GROOVES were indicated by a longitudinal mid-dorsal row of 
elongate pigmented tubercles, but there were no perceptible traces of the facial, 
lateral, or pedal grooves ; the MANTLE was invariably intensely black with a violet 
tinge; the OMMATOPHORES were moderately long, colourless and transparent, and 
overspread with minute grey granulations, the retractors being more or less deeply 
pigmented and visible through the transparent skin and traceable along the sub- 
dorsum to their junction with the retractors of the anterior tentacles of their 
respective sides; the EYE-SPECKS are quite black and sub-apical, being less laterally 
directed than in certain other species ; the ANTERIOR TENTACLES are comparatively 
long and similar in aspect to the ommatophores ; the FOOT-SOLE is elongate, of an 
uniform creamy-white, and without perceptible longitudinal fasciation or division. 
The average amount of manganese present in the tissues of XY. virgata is stated 
by Prof. Boycott to be 0-001 per cent. of the total weight of the animal. 
INTERNALLY, the organization is in general conformity with that of its allies, 
but the KIDNEY is very elongated and pointed at one end and has been likened to 
a scythe-blade. 
\ 
bic. 219. Fic. 220. 
Fic. 219.—Brain-ring or Nervous-centres of . vi7gata Da Costa, greatly enlarged. 
Fic. 220.—Heart of X. virgata var. variadilis Draparnand, from Malta, x 3, showing auricle 
and ventricle within pericardium, and displaying the close relationship with the kidney. 
The NERVOUS SYSTEM is largely concentrated in the NERVE-COLLAR or brain- 
ring, as in the normal Helicidian type, the cerebral pair are closely approximate 
and somewhat elongate, but not tumid, with thickened junction, which obscures 
the commissure; the cerebro-pedal and cerebro-visceral centres are stout and fairly 
elongate, pedal pair and visceral ganglia being fused into one mass, the pleural 
ganglia being indicated by a thickening of the connective cords and feeble pig- 
mentation ; the pedo-visceral complex is pierced by the aorta, while the buceal- 
bulb is protrusible beyond or can be drawn within the cerebro-pedal ganglia. 
The REPRODUCTIVE ORGANS present a linguiform gelatinous ALBUMEN GLAND, 
of a greyish colour with a greenish tinge, the ceca of the OVOTESTIS are white and 
lobulate, the HERMAPHRODITE DUCT is attenuated at each end, but thickened 
medially ; the VESICULA SEMINALIS dark grey, the blind end paler and spotted ; 
the OVIDUCT sacculate, of a dull yellowish-grey or yellowish-brown ; SPERM DUCT 
Fic. 221. Hres222s Fic. 223. 
Fic. 221.—Stylophore or dart-sac of an adolescent example of X. virgata var. variabilis Drap., 
from Malta, showing its bifid distal end, x 4. 
Fic. 222.—Vaginal mucus-glands of Y. virgata var. maritima, from Corfe Castle, Dorset, x 3. 
Fic. 223.—Stylophore of X. virgata var. maritima, from Corfe Castle, Dorset, showing the 
bifid summit of the stylophore, x 6. 
d.s. stylophore or dart-sac; .s. the severed end of penis-sheath ; v. the severed vagina. 
white and granular; SPERMATHECA usually subtriangular, but often elongate in 
shape, of a reddish-flesh colour, though occasionally whitish and slightly spotted ; 
the stem or duct fairly long and stout, but thickened basally and without diverti- 
culum. MUCUS GLANDS two on each side, each gland being variously divided into 
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