Introduction to Animal Morphology. 3 1 1 



lariadae freshwater ; foot large ; eyes on short stalks ; pul- 

 monary cavity coexisting with the gills. 



V. Neurobranchiata terrestrial, dioecious, operculige- 

 rous, breathing air by a vascular net-work on the roof of the 

 mantle cavity : tentacles two, non-retractile, behind or at the 

 base of which are the eyes ; penis anterior. This includes: 

 i. CVclostomidce shell conical, taenioglossate, often de- 

 pressed ; foot long ; mouth round or oval, entire or with a 

 double margin ; operculum paucispiral or multispiral, horny 

 or calcareous. 2. Stoastomidae shell conical ; columella 

 flattened ; eyes at the base of the tentacles ; radula rhipido- 

 glossal ; operculum not spiral, but semicircular, triangular, or 

 none. 3. Aciculida? foot small ; lips parallel ; peritreme 

 thickened (Acicula), or canaliculated below (Geomelania). 



Order 2. Pulmonata (Cuvier) air breathing, symmetrical, 

 terrestrial, herbivorous, hermaphrodite Gasteropods, naked, 

 or shell-bearing, with no operculum, except in Amphibola. 

 The lung is behind the heart, and the larva has no con- 

 spicuous velum. The shell is deposited not outside, but as 

 calcareous granules, in the mantle substance. They are very 

 abundant in warm climates. They are divisible into three 

 sub-orders : 



i . Accra with no tentacles, including the Australian 

 family Amphibolidae, living in brackish water; with the penis 

 under the right eye ; shell umbilicate, globular. 



Sub-order 2. Stylommatophora eyes on the ends of 

 stalks or processes of the body wall (hinder tentacles), which 

 may be contractile and coexisting with two other simple ten- 

 tacles, as in Veronicella, or with no other tentacles, as in 

 Onchidium ; or the tentacles may be two ; retractile, as in 

 Janellidas ; or four retractile, as in the following families: 

 Limacidx- shell hidden in the mantle- (which is fused with 

 vs strong, crescentic. Arion has a shell of 

 and a caudal gland, as in Geomalacus, while 

 Umax, the common tail gland. I'annaeella has 



'. 2. Testacellidss- carnivorous, small ; jaws 



i may inelude the whole budy :'( ilaiulina), and 



may 1. :>liquc(Si: ; it is rarely conical, 



multi ella and Dan- 



