MONOGRAPH OF BRITISH LAND AND FRESHWATER MOLLUSCA. 121 
Sus-Genus Hydrolimax A. W. Malm. 
Agriolimax levis Miiller. 
1774 Limax levis Miller, Verm. Hist., ii., p. 1, no. 199. 
1801 — brunneus Drap., Tabl. Moll, p. 104, no. 13. 
1822. — Jlacustris Bonelli, in Sched. Mus. Taurin. 
1841 — campestris Binney, Proc. Boston Soc. Nat. Hist., p. 52. 
1845 — Jlombricoides Morelet, Moll. Port., p. 39, pl. 3, f. 4. 
1852. — parvulus Normand, Dese. Lim. Nouv., p. 8. 
1867 — «arenarius Gassies, Malac. Aquitaine, pp. 117-119, pl. 1, f. 1. 
1874 — argentinus Strobel, Mal. Arg. Merid., p. 6. 
1875 — montanus Ingersoll, Bull. U.S. Geol. Surv. Terr., p. 394. 
1875 — _ castaneus Ingersoll, op. cit. 
1875 — ingersolli W. G. Binney, Proc. Acad. Nat. Sci. Philad. 
1876 — = hyperboreus Westerlund, Nachsbl. d. Deutsch. Mal. Ges., p. 97. 
1878 = — meridionalis Doering, Bol. Acad. Cordoba, p. 434. 
1889 — _ stenurus Strebel, Faun. Mexik. Conch., p. 21. 
1885 — brasiliensis Von Ihering, Jahrb. Deutsch. Mal. Ges., p. 201, pl. 5. 
1888s — queenslandicus Hedley, Proc. Roy. Soc. Queensland, p. 150, pl. 5. 
1871 — (Agriolimax) rarotonganus Heyn., Nachbl. d. Deutsch. Mal. Ges., p. 45. 
1882 Agriolimax levis Lessona & Pollonera, Monog. Limac. Ital., p. 47. 
1897 -— bevenoti Collinge, Proc. Mal. Soc., vol. 2, p. 295. 
1868 Hydrolimax levis Malm, Limac. Skand., p. 79, pl. 3. 
1868 Krynickillus (Malino) brunneus Mabille, Rev. et Mag. Zool., p. 141. 
1887 Arinichia brunneus Fischer, Man. Conch., ii., p. 462. 
ISTORY. — Agriolimax laevis (levis, 
smooth) was first discovered in this 
country by Mr. Joshua Alder, and its 
peculiar characters pointed out to Dr. G. 
Johnston, who published the discovery in 
1838 in the Proceedings of the Berwick- 
shire Naturalists’ Club. 
‘The species was, however, afterwards 
lost sight of, neglected or misunderstood, 
and became relegated to the ranks of 
doubtful species by Jeffreys, Reeve, and 
others, despite the persistent efforts of 
Mr. E. J. Lowe, F.R.S., to secure the 
recognition of its specific status. 
The authoritative exposition of its m- 
ternal structure by Dr. Simroth has firmly 
established A. ldwvis as a valid species, 
which is now universally recognized. 
With this species is associated Dr. J. I. 
7 C3. Babor, of Prague, whose profound re- 
ae JX ate, searches, more especially upon A. levis, 
a ; have demonstrated the actuality of a 
remarkable cycle of changes in the development of the reproductive organs. 
It was placed by Malm in a new genus, Hydrolimax (“dwp, water, and 
Limax), which is here adopted in a sub-generie sense to mark the absence 
of the rectal ccecum and the digitate flagellum. 
Diagnosis.— A. lwvis may be distinguished from A. agrestis by its active 
and restless habits, its uniform red-brown colour, colourless mucus, the abrupt 
terminal end of the body, the large shield, and its nearly median position 
when the animal is fully extended, owing to the unusual length of the neck. 
INTERNALLY, it is sharply divided from A. agrestis by the total absence 
of the rectatheca and of the digitate gland at the apex of the penis-sheath. 
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