MONOGRAPH OF BllITISH LAND AND FRESHWATER MOLLUSCA. 21 



Testacella maugei Ferussac. 



1801 Testacella haliotoidcs Lam., Sys. An. s. Vcr., p. 96 (nomeii nudum). 

 1805 — haliotidea pars, Drap., Hist. Nat. Moll. Finance, pi. 8, ff. 46-48. 

 1819 — maugei Fer., Hist. Moll., p. 94, pi. 8, if. 10-12 ; Keeve, Brit. Moll., 186S, 



p. 32 and ff. ; Adain.s, Coll. Manual, 1896, p. 41, pi. 2, f. 3. 

 1827 — asiiiiniim de Serres, Ann. Sc. Nat., p. 409. 



1850 — lartetii Dupuy, J. de Condi. , i. , pp. 302-4, pi. lo, ff. 2 a— d. 



1851 — bnmtonlana de Serres, Mem. Terr. Transp., p. 51. 



1855 — haliotidea v. scutiilum Moq.-Tand., Hi.st. Moll. France, pi. 5, ff. 20, 21. 



1855 — hurdiqalen^k, Gassies, Cratelou]i's Blst. Geo<{. Liniacien.s, p. 15. 



1855 — occanica Gi-ateloup, Dist. Geog. Liniaclen,':, p. 1.5. 



1855 — aquitanica Grateloup, Dist. Geog. Limaciens. p. 16. 



1835 — broiDniana Grateloup, Dist. Geog. Limaciens, p. 16. 



1855 — occitanicB Grateloup, Dist, Geog. Limaciens, p. 16. 



18S3 — monspessidana Grateloup, Dist. Geog. Limaciens, p. 16. 



1835 — cannneiisis Grateloup, Dist. Geog. Limaciens, p. 16. 



1855 — altw-ripa; Grateloup, Diist. Geog. Limaciens, p. 16. 



1855 — deshayenii Michaud, Deso. Coq. Foss., p. 3, pi. 2, ff. 10, 11. 



1881 — Houleti Bourg. , Hist. Mai. CoUine de Sansan, p. 15. 



1819 Plectrophoriis orbignyi Fer., t. Simrotli, Nacktsclinecken Portug.-Azovisclien, 

 1891, p. 404. 



History. — Testacella maugei was discovered at Teneriffe in 1796 by 

 M. Maug^, in whose honour it was named by Fdrussac, and according to 

 Dr. Turton, was said to have been first found iu England by Mrs. Smith, 

 in her garden at Bristol ; in 1812 Mr. T. Drummond detected it in Miller 

 and Sweet's (now Caraway's), Diirdham Down Nurseries at Clifton, Bristol, 

 and sent specimens to Dr. Leach, which were forwarded to aud figured by 

 Ferussac. 



Although a very distinct species it is far from being accurately known, 

 and from the earliest period has been aud is still often confused with T. halio- 

 tidea by otherwise competent conchologists. M. Draparnaud figured un- 

 doubted T. maugei as the adult form of T. haliotidea, while Moquin-Tandon 

 also figures what is probably the present species as T. haliotidea v. scutulum. 



Gassies and Fischer, the able monographers of the genus, in tlieir great 

 work, "Monographie du genre Testacelle" (pi. i., f. 15) illustrate the repro- 

 ductive organs of T. haliotidea, but erroneously ascribe them to the present 

 species ; this unfortunate confusion was accepted and endorsed in some of 

 their writings by the famous limacologists, Simroth aud PoUonera, and to 

 add to these regrettable mistakes, the brilliant French biologist, Prof Lacaze- 

 Duthiers, has in his otherwise masterly work, " Histoire de la Testacelle," 

 perpetuated further misapprehension of the organization of this species, 

 with which he was evidently unacquainted. 



The organization of T. maugei is of a simpler and more primitive type 

 than that of its congeners, and its more marked restriction to the confines 

 of Western Europe confirms this species as being the most ancient form of 

 our TestacellcB. 



Diag:nosis. — Externally, T. maugei is readily recognisable by its large, 

 convex, and semi-cylindi'ical shell, and by the lateral grooves upon the body 

 of the animal being so wide apart at their origin at the peripallial furrow. 



Internally, the distinctive features are even more striking, the lingual 

 sheath being quite deficient of lateral muscles and possessing only terminal 

 retractors, while the right and left tentacular retractors are both affixed to the 

 integument quite on the left side of the animal; the penis sheath differs 

 from that of T. scutulum in its strikingly clavate shape, and from 2\ halio- 

 tidea in the absence of the flagellum which is so marked a featm-e in that 

 species. 



