Xli CLASSIFICATION OF OLEACINID.E. 



II. CLASSIFICATION OF THE OLEACINID^. 



Family OLEACINID^E Gray. 



Oleacinidcc GRAY, Ann. Mag. Nat.-Hist. 1860, iv, p. 267. 



Holopoda with a pair of dorsal but no lateral furrows; no 

 coherent jaw; radula armed with unicuspid thorn-shaped 

 teeth; cerebral ganglia concentrated, the commissure very 

 short. Lung (pi. 52, fig. 7, Oleacina oleacea straminea) with 

 dominant pulmonary vein and profuse branching venation; 

 kidney triangular, the short side against the pericardium, 

 whence it extends obliquely backward and towards the gut. 

 Genitalia haplogonous or with accessory penial organs. Shell 

 elongate, never depressed, spiral, generally capable of con- 

 taining the soft parts, the aperture narrow or small, colu- 

 mella usually truncate or sinuous at base. Oviparous, the 

 elliptical egg-capsules hard-shelled, roughened and white. 



This family is chiefly tropical American, but one genus oc- 

 curs in the Mediterranean region, and fossil forms occur 

 throughout the European tertiaries. Qleacinida are active, 

 rapacious snails, living in the haunts of ground-snails, upon 

 which they chiefly feed. Eiiglandina rosea, which I have 

 kept in captivity, perceives its prey from a distance of at 

 least eight inches, whether by sight or odor is unknown. Glid- 

 ing rapidly toward it, when within striking distance the 

 Eiiglandina lunges swiftly, seizing the snail by the back. 

 The almost instantaneous withdrawal of the victim into its 

 shell does not loosen the hold of the Eiiglandina. which 

 quits the feast only after the greater part has been devoured. 

 In one instance, E. rosea was occupied eight hours in eating 

 a large Helix (H. vermiculata) , the fore part of the body 

 being thrust into the aperture of the Helix so far that the 

 peristomes of the shells were brought, in contact. The actions 

 of Poiretia algira have been described by Henking as similar 

 to what I have observed in Eiiglandina. The stomach of 

 Eiiglandina rosea frequently contains entire shells of small 

 Helices which have been swallowed whole. The swift move- 

 ments of Eiiglandina in attack contrast with the deliberation 

 of most land snails. 



