HYALINIA RADIATULA. 89 
Diam., 4 mill. ; alt., almost 2 mill. 
The shell in crawling is borne elevated on the left rear side of the body, and 
during progression sways perceptibly from side to side. 
When containing the retracted animal, the shell shows the reddish-brown 
digestive gland with its delicate whitish reticulations, the colour gradually paling 
until the dark collar of the mantle is reached. 
Beneath, the brownish digestive gland with indistinet black marblings fills 
the major part of the shell, and it becomes increasingly blackish towards the 
periphery and beyond the pale renal organ, 
When crawling, the shell beneath shows only the dark mantle collar and three 
digitiform, fawn-coloured lobules of the digestive gland, the remaining space being 
fairly clear. 
The ALIMENTARY ORGANS are described by Dr. Lehmann 
as showing a short GESOPHAGUS, surrounded by the ample 
and yellowish SALIVARY GLANDS ; the CROP or stomach as 
elongately fusiform and bent in a erescentie shape, its 
walls showing strong, transverse musculature ; and the 
INTESTINAL TRACT as long and convoluted. 
The REPRODUCTIVE ORGANS exhibit the OVOTESTIS 
with a moderately long and convolute HERMAPHRODITE 
DUCT; ALBUMEN GLAND large, linguiform, finely granular 
and of a milky-white color; SPERM-DUCT narrow and 
ribbon-like, continuing as a moderately long and sinuous 
VAS DEFERENS, which enters the penis sheath at its distal 
end; PENIS SHEATH short and pyriform, with a short 
terminal retractor affixed close by the point of entry of 
the vas deferens ; OVIDUCT or matrix very sacculate, con- . 
stricted above at its junction with the albumen gland, _ F's. ale Sora NE 
greatly amplified below ; FREE OVIDUCT moderately long, (liter Lehmann) 
VAGINA short and wide, beneath the yellowish-brown 
cloak ; SPERMATHECA claviform and transparent, the vesicle exceeding a mill. in 
length, supported by a very slender stem. 
The JAw of a Hyalinia radiatula from Swarraton, 
in Hants., is of the usual horny-brown colour, very 
deep, strongly arched, with unusually broad lateral 
limbs, terminating in an acute outer point; the median 
rostrum or beak is somewhat narrow, but well-marked Ric. Ise Mandible ortau or 
and prominent, and the line of insertion into the 7. yadiatuda Alder x 30. (Swar- 
tissues is clearly perceptible. raton, Hants., Rev. W. L. W. Eyre). 
The LINGUAL RIBBON of a Swarraton specimen is of the usual elongate shape, 
about a millimetre in length, and about a quarter of a millimetre in width, and 
composed of about seventy-five partly-curved transverse rows of teeth. Each row 
is composed of a large distinetly tricuspid median tooth on a broad sub-triangular 
base, furnished with a long and powerful mesocone and a distinet eetocone on each 
side, all with well defined cutting points. The admedian or lateral teeth are 
A aaa 
Fic. 133.—Half a transverse row of the teeth of Hyadinia radiatula x 600, from Swarraton, North 
Hants., Rev. W. L. W. Eyre. : 
The formula of a Swarraton specimen is 
25434543422 x 715 = 2,875. 
three in number, and all are practically bifid, each presenting a well-developed 
mesocone and ectocone. The marginals are about twenty-five in number, all 
strictly aculeate in shape, without any transition teeth linking them with the 
laterals, and decreasing rapidly in size as the outer margin 1s approached, 
( 
