LIMACINEA. ( 



through the press, accompanied by a letter, written with his wonted 

 enthusiasm, informing me that it has been most abundant in his 

 garden during the present year. Testacella has also been observed 

 in the West Indies at G-uadaloupe and Martinique, but hardly suffi- 

 ciently to prove that it is indigenous to those islands. 



The genus OncJiidium included in this Family by authors is a sea 

 slug. It is a native chiefly of New Zealand and the Friendly 

 Islands ; a small species occurs on the shores of Brittany and Corn- 

 wall, congregated in little groups on the rocks, where the waves 

 break over them. 



The genera of British Limacinea are : — 



1. Arion. Body rounded on the back, a terminal pore at the 



tail extremity, pulmonary sac near the head, respiratory orifice 

 in front, shield granulated. Shell wanting, or represented 

 by a few isolated or agglomerated grains. 



2. Geomalacus. Body rounded on the back, pulmonary sac near 



the head, respiratory orifice quite in front, shield smooth. 

 Shell, a solid oval plate. 



3. Limax. Body more or less keeled on the back, pulmonary sac 



near the head, respiratory orifice more or less behind, shield 

 sometimes granulated, sometimes concentrically striately 

 wrinkled. Shell, a solid oval plate, passing into a valve de- 

 veloped in symmetrical order from an umbonal nucleus. 



4. Testacella. Body rounded, tapering towards the head, pulmo- 



nary sac near the tail extremity, covered by a lobed mantle 

 secreting an external shell. Shell ear-shaped, enlarged from 

 a sub-spiral nucleus. 



Genus I. ARION", Ferussac. 

 Animal ; body cylindrical, elongated, rounded on the back, and 

 furnished with a mucus-pore at the posterior extremity, integu- 

 ments crowded with oblong tuberosities or with leaflets; head 

 with two pairs of tentacles, the upper pair being much the longer, 

 with minute eyes at their bulbous extremity ; shield at the front 

 part of the body, covered with fine granulations, respiratory 

 orifice at the right margin, a little anterior to the centre ; shell 

 wanting, or represented by a few isolated or agglomerated 

 grains. 

 The slugs of this genus are distinguished from those of Limax 



