246 HUGH WATSON. 



cella^ Daudebardia, and tlie Trigonochlaminse, but some- 

 times also ill the Oleacinidse, Rhytididte, and Aperida3. 

 I have already described them in Apera, where they may 

 be very conspicuous (PI. VII, figs. 11 and 13). Collinge^ 

 shows them in his figures of Schizoglossa novoseelan- 

 dica {Pfr.), and they are present on both sides in Natalina 

 quekettiana [M. & P.), though rather ill-defined. In 

 Euglandina venezuelensis {Preston) I have also found 

 both lateral grooves, but the right groove is more conspicuous 

 than the left. In these genera, however, the right lateral 

 groove ends in the genital opening, whereas in Daude- 

 bardia it passes below the genital opening and unites with 

 the peripodial groove.- Now, Testae ella differs from 

 Duudebardia in this respect, and agrees with the other 

 families of carnivorous snails.^ 



In Daudebardia there is a deep peripodial groove, cutting 

 off a broad foot-fringe, wdiich is cleft at the hind end by a 

 short groove probably representing the lost mucous pore.* 

 A peripodial groove is also present in the Aperidse and 

 Streptaxida3, and although it is often absent or only slightly 

 developed in the Rhytididse and Oleacinidte, Reymond 

 states that it is fairly deep in Poiretia. In these forms, 

 however, there is no trace of a caudal mucous pore. This is 

 also the case in Testacella, which possesses a peripodial 

 groove shallower than that of Daudebardia and nearer the 

 edge of the foot.''' 



Lastly, Daudebardia resembles the Trigonochlaminte, 

 Limacinge, and related groups, in having two conspicuous 

 longitudinal grooves on the foot-sole, approximately parallel 

 to each other. As a rule no such grooves are found in the 

 other families of agnathous snails and slugs, but we have seen 

 that occasionally similar grooves occur towards the hind end 



1 'Ami. Mag. Nat. Hist.' (7tli ser.), 1901, vol. vii, pi. ii, figs. 26, 27. 



2 Plate, L. H., • Zool. Jahrb.,' 1891, vol. iv, pi. xxxii, fig. 1. 



' See de Lacaze-Dutliiers, ' Arcli. Zool. Exper.,' 1887, vol. v, pi. xxx. 

 fig. 11. 



■» Wiegmann, F., 'Mitt. Zool. Samml. Mus. Berlin.' 1898, vol. i, p. 62. 

 * Compare Plate's figs. 3 and 11 on pi. xxxii, op. cit. 



