APPENDIX—-VITRINA TTIBERNICA. .- 453 
the ectocone being more basally placed and more strongly developed than the 
endocone, which gradually diminishes in size and prominence ; the inner marginals 
are bifid, the endocone of the lateral teeth having become obliterated, and the 
ectocone also being much reduced in importance until at about the twentieth row 
it also disappears and the teeth become simply aculeate, the extreme outermost 
rows being quite rudimentary. j 
27 28 3239 ss 
RAK ee 
Fic. 517.—Representative teeth from the radula of Ittrina hibernica, showing median, lateral, 
and marginal teeth (from a highly-magnified photograph by Mr. W. Bagshaw of a preparation by 
Prof. Gwatkin). : 
Formula 74 +42 +4+142+ 34187 = 9,525 teeth. 
_ The REPRODUCTIVE ORGANS show an OVOTESTIS composed of an oval aggrega- 
tion of acini; the HERMAPHRODITE DUCT is short and almost direct, terminating 
near the base of the long and slender VESICULA SEMINALIS ;_ the ALBUMEN GLAND 
is lobulated and ample; the OvipUCT is sacculated and folded, continuing as a 
nearly straight FREE OVIDUCT, from whose upper section, the globose, short- 
stemmed SPERMATHECA arises; the SPERM-DUCT is slender and runs with the 
saceulate oviduct, being continued as the VAS DEFERENS to the short and stout 
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Fic. 518. Fic. dlY. Fic. 520. 
teproductive organs of I”, hibernica, after a dissection by Dr. Simroth. 
Fic. 519.—Sexual system showing the arrangement of its various constituent organs, x 10. 
ot. ovotestis ; alé.g7. albumen gland ; a.g. genital atrium; d@.gé. dart gland, enclosing papilla or 
dart ; 4.d. hermaphrodite duct; 0. free oviduct ; #. penis sheath ; faf. papilla ; sf. spermatheca ; 
sp.d. sperm duct; wf. uterus; v.d. vas deferens ; v.s. vesicula seminalis. 
Fic. 518 and 520.—Papilla from the dart-sac showing two of the stages of its development ; more 
highly magnified. d.gl. dart gland ; fa. papilla. 
PENIS SHEATH, which it enters about midway ; the DART GLAND is a long con- 
spicuous organ, glandular at the distal end, and containing a papilla or dart, 
with a short crenulated chitinous crown, hardened or strengthened by chitinous 
rods, the length of the papilla varying in different specimens according to the 
development of the gland. 
Habits and Habitat.—Vitrina hibernica, though found in other 
situations, apparently prefers the wooded portions of the country it 
inhabits, often congregating in the damper areas. — It is very plentiful 
over a wide area of the ancient woodlands of Lord Massareene’s 'l'emple 
demesne at Collon, Co. Louth, where it was first found, the woods there 
being composed of native oak, beech, ash, ete., with planted larch, laurel, 
and various shrubs, 
