72 LIMAX TENELLUS. 
Description.— ANIMAL slender, very soft and viscous, with about thirty longitu- 
dinal rows of rugze on each side of the body, of a pale yellowish, yellowish-grey, or 
ereenish-white, but occasionally of a golden-yellow with orange shield, an obscure 
hand on each side of the body and shield ; SKIN soft and thick, becoming thin and 
tender when the animal is placed in alcohol, a change probably due to the large 
amount of mueus which is thrown off; HEAD and TENTACLES black or blackish- 
brown; hinder fifth of the body somewhat but not acutely keeled ; SHIELD very 
obtusely angulated behind ; SOLE transparently whitish or yellowish and tripartite ; 
owing to this transparency of the median-area the foot-gland is clearly visible when 
the animal is crawling, and is seen to extend to the hinder-part of the body; the 
glandular lobules are also seen attached to the median-duct; MUCUS in half-grown 
or adult individuals of a yellow or orange colour. Length, 25-35 or more mill. 
SHELL somewhat oblong, whitish, thin, and . 
arly transparent, slightly concave beneath, apex Fic. 85.—Interna 
nearly : = Sie Banat J ; : rcp My a zy shell of ZL. tenellus 
nearly terminal, with the usual concentric LINES ‘ sone eeipeies de 
is . . .’ 4 2) . 
OF GROWTH, margin rather broad, thin, and imem- ‘NS Simroth). 
branous. Length, 3$ mill. ; breadth, 2 mill. . 
INTERNALLY, the NERVOUS SYSTEM conforms to the general type, but the organ 
of Semper is horse-shoe shaped, like that of L. mains, differing, however, in the 
cells being aggregated into five larger lobes around the mouth. The OSPHRADIUM 
is not distinctly perceptible, but may be detected by the slight furrowing defining it. 
o°o 
Fic. 86.—Otolith of Limax 
tenellus, highly magnified (after 
Schmidt). 
Fic. 87. 
Tic. 8& Fic. 89. 
Fic. 87.—Sexual organs of Z. tened/us Mill. x 3 (after Simroth). aéé.g. albumen gland ; /. heart ; 
k. pdney ; ov. oviduct; of. ovotestis ; f. prostate; Z.s. penis sheath; 7. retractor muscle; sf sper- 
matheca, 
Fic. 88.—Penis-sheath of Z. tened/us laid open, showing its internal structure, x 6 (after Simroth). 
Fic. 89.—Alimentary canal of Linear tenel/us Mill., X 3 (after Simroth). 
The REPRODUCTIVE ORGANS are not complex; the OVOTESTIS is small, placed 
behind the stomach, and surrounded with dark-brown tissue; DUCT dark-brown, not 
convolute but greatly swollen in the middle of its course, and ending in a tiny 
spherical and white VESICULA SEMINALIS ; ALBUMEN GLAND yellow, tender, and 
flaky; OVISPERMATODUCT relatively shorter than in Limaaz maximus, and only 
slightly connected together ; OvIDUCT pale above, yellowish below, narrowing bas- 
ally, and forming a thickened yellow base; SPERM-DUCT delicate above, but becoming 
a broad yellow glandular channel below, ending in a short broad VAS DEFERENS, 
which widens like a funnel, with a loose, plicate crest at its entry into the penis; the 
RETRACTOR arises from the same spot as a broad museular band, and is distally 
attached to the floor of the lung, in the median-line in advance of the heart ; SPER- 
MATHECA oblong, with a long, slender stem, opening into the atrium; PENIS-SHEATH 
short, thick, and white, with a lateral protuberance near the base ; interiorly there 
is a long, flatly projecting and finely plicate comb or crest, which is richly glandular, 
and encircles the opening of the vas deferens. 
The CEPHALIC RETRACTOR arises as a simple broad, muscular band, in the 
median-line of the body, behind the lune. It does not divide into the normal three 
branches until the middle of its length. 
The ALIMENTARY CANAL is set in delicate and black mesenteric tissue, and has 
five intestinal tracts in addition to the stomach tract as in Limax maximus, and is 
an almost exact counterpart of those of the very young examples of that species, 
