190 LITERATURE OF THE GASTROPODA 
animals, without a shell ; the female orifice on the right in the middle of the 
body ; the anus posterior. Genus—Vaginula, Férussac (Fig. 179), Famrity 
2. OncripDAE, Philippi. Limaciform naked marine animals, without a 
Fig. 179. 
Vaginula luzonica. A, dorsal aspect; b, ventral aspect. I, posterior tentacle ; II, anterior 
tentacle ; III, mouth; IV, mantle; V, female orifice; VI, foot; VII, anus. (After Souleyet.) 
shell ; female orifice near the anus, at the posterior end of the body ; 
reduced pulmonary cavity with a distinct pneumostome (Fig. 59, pus). 
Genera—Oncidium, Buchanan ; body elongated and narrow; penis with 
Fic. 180. 
- Oncidiwm tonganum, left-side view. (From Lankester, after Quoy and Gaimard.) 
accessory apparatus; from the Indian Ocean. Oncidiella, Gray ; body 
oval; mantle thick, with an emarginated border ; penis without accessory 
apparatus ; British (Fig. 59). Peronia, Blainville ; body oval ; the mantle 
covered with ramified appendages and oculiferous tubercles. 
LITERATURE OF THE GASTROPODA. 
A. Gastropoda generally. 
1. Amaudrut. La partie antérieure du tube digestif et la torsion chez les 
Mollusques Gastéropodes. Ann. des Sci. Nat. Zool. (8), vii. 1898. 
2. Backer. Die Auge einiger Gastropoden. Arb. Zool. Instit. Wien, xiv. 1902. 
3. Baudelot. Necherches sur l'appareil générateur des Mollusques Gastéropodes. 
Ann. des Sci. Nat. Zool. (4), xix. 1863. 
4. Boutan. La cause principale de l’asymétrie des Mollusques Gastéropodes. 
Arch, de Zool. Expér. (3), vil. 1899. 
