File:Image from page 181 of "Introduction to zoology; a guide to the study of animals, for the use of secondary schools;" (1900) (14782658574).jpg

Identifier: introductiontozo00dave Title: Introduction to zoology; a guide to the study of animals, for the use of secondary schools; Year: 1900 (1900s) Authors: Davenport, Charles Benedict, 1866-1944 Davenport, Gertrude Anna Crotty, 1866- Subjects: Zoology Publisher: New York, Macmillan company London, Macmillian and co., ltd. Contributing Library: MBLWHOI Library Digitizing Sponsor: MBLWHOI Library

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Text Appearing Before Image: gth of about10 centimetres and has a light brown color, marked withlongitudinal rows of black spots along the back and sides. This species was almost un-known in this country untilthe middle of the sixties, butit is now widespread through-out the East. It has doubt-less been introduced from thecontinent of Europe, whereit is very abundant. Second,Limax ay rest is1 is usuallyabout 2.5 centimetres long ;it varies in color from whitishthrough gray to black. It isnow common in the easternUnited States, but is believedto have been introduced fromEurope. Third, Limax cam- genera figured are: A, Actaeon; pestris? a native species, isB, Aplustrum; C, Cylicbna; D, , , Atys; E, Phiiine; F, Doiabeiia; smaller than agrestis, and its tuberosities are not somuch flattened or plate-like.It occurs widely distributedeast of the Rocky Mountains. Economically, slugs are of importance because at timesin some localities they cause much destruction in gardens 1 Living in the field. 2 Living in open fields.

Text Appearing After Image: FIG. 149. — Illustrating the transi-tion of form in the shell of certainOpisthobranchs, from the pointedspiral to the almost tiat plate. The G, Aplysia; //, Pleurobranchus.Drawn to various scales. FromCooke, Mollusca. THE SLUG AND IM ALLIED 168 .c.d ep- and greenhouses. Particularly in Europe, Limax agrestishas often devastated fields of young shoots ; this speciesis especially fond of bulbous plants. In the apparent absence of a shell the slug seems to bean aberrant gastropod. Other land gastropods — thesnails — have an evidentshell. In Limax the shellis reduced to a thin, horny ^ Jplate, embedded in themantle. Between the con-dition seen in the snailand that in Limax thereare intermediate condi-tions, in which the largeshell is partly covered bythe mantle, and othersin which the shell hasbecome reduced in size.In allies of Limax -

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