HYALINIA LUCIDA. 21 
= 
and terminal, passing through the right tentacular loop and becoming attached to 
the upper part of the oviduct ; the SPERMATHECA is variable in shape, digitiform or 
crescentic, rarely oval, semitransparent, with a bright red or reddish-brown core, 
united to the oviduct by a muscle at the crown; its duct is about double the length 
of the vesicle, and sometimes striped longitudinally with opaque white, thin above, 
but gradually widening below, abruptly flexed a little below the vesicle and attached 
to the ovidnet ; FREE-OVIDUCT slender above, becoming more ample below the cream 
coloured VAGINAL GLANDS, conspicuous and massed around the free-oviduect, con- 
cealing the junction of the spermatheca duct ; ATRIUM or vestibule very short. 
= 3 
“ IZov 
siy* rd 
a? d WO 
aM sd i\4 
af ot. ; ss 
= 
~ ; 
ete ~~ 
Fic. 40. Fic. 41. Fic. 42. Fic. 43. 
Fic. 40.—Reproductive organs of //. /wcida (Drap.), x 3. (Torquay, Mr. J. T. Marshall). 
a.g. albumen gland ; ef. epiphallus ; of. ovotestis ; ov. oviduct ; s.d. sperm duct; sf. spermatheca ; 
v.d. vas deferens; 7. retractor ; f.ov. free oviduct ; g. vaginal gland ; #.s. penis sheath. 
Fic. 41.—Penis-sheath, epiphallus, and vas deferens, showing indications of their internal structure 
as visible by transmitted light, x 6 (after a photo. by Mr. W. Moss). 
Fic. 42.—Alimentary canal of Hyadinia lucida (Drap.), showing the salivary glands and the mode of 
retention of the first anterior intestinal tract by the cephalic artery, x 3 
Fic. 43.—Cephalic retractors of Hyalinia lucida (Drap.), X 3. 
The ALIMENTARY SYSTEM displays a dark, dusky, and elongate G&SOPHAGUS, 
longitudinally striped with a darker shade, around which are the large dull 
yellowish SALIVARY GLANDS ; the wsophagus expands into a broad and long sub- 
cylindrical crop, which blends with the STOMACH at the termination of the INGES- 
TIVE TRACT, where an abrupt flexure originates the INTESTINE, which is of the 
usual triodromous type,! but with inconspicuous flexures, of a greenish-grey colour, 
rather broad at the origin, but gradually narrowing ; DIGESTIVE GLAND dark 
brown, with arterial system indistinct, the bile ducts discharging as is usual at 
the commencement of the second intestinal tract. 
The CEPHALIC RETRACTORS are a series of very powerful muscular straps arising 
from the upper surface and base of the columellar muscle. The two TENTACULAR 
retractors are uppermost and conjoined at their origin. The broad PHARYNGEAL 
branch originates immediately beneath the tentacular muscles, and before fixation 
to the buccal bulb gives off a strong muscular slip to the foot. 
The MANDIBLE or jaw is very convex, rather more 
than one millimetre across from side to side, of a 
very deep reddish amber colour, shading into an 
opaque deep brown at its greatly thickened upper 
margin; on the middle of the concave or cutting- 
edge there is a blunt, broad, and only slightly pro- Se ee ee 
jecting rostrum or beak, while the ends of the jaw Hyalinia lucida (Drap.), X 20. 
at each side are somewhat sinuous and inclined to (Bristol, Miss F. M. Hele). 
be rather falciform at the outer angles. 
The LINGUAL RIBBON is comparatively large and of an oblong shape, about 
5 mill. long, and about 1°25 mill. wide, composed of about thirty loosely ranked 
and slightly eurved transverse rows of teeth, which converge towards the median 
line of the radula. Each row is composed of a small and distinetly tricuspid 
median tooth, with a long mesocone when unworn, but exceptionally showing @ 
1 Monog. i., p. 284, f. 567. 
