Suter. — On Nero Zealand MoUusca. 247 



shouldered and with traces of stout setae ; covered with a dark- 

 brown coating ; there are seven whorls, the peritreme is con- 

 tinuous. The dimensions range from 7 x 4| mm. to 6 J x 4f mm. 



Potamopyrgus corolla, Gould, subsp. salleana, Fischer 



(1860). 

 Paludestrina salleana, P. Fischer, Journ. de Conch., vol. viii., 

 1860, p. 208, pi. iv., fig. 6. 



(1.) Lake Waikare (Stat. 14 and 14f — Among reeds). — From 

 Stat. 14 are thirteen adult and a number of young shells ; from 

 Stat. 14f twelve specimens, exactly the same as the former. 

 Most of them are of horn-colour, with a white calcareous coating ; 

 three only are coated with black. All, with the exception of one, 

 are spinous, the spines being distant, rather short, bent upward. 

 In some specimens a distinct angle below the periphery is present. 

 All the adult shells are smaller than the type, with six whorls. 

 The dimensions range from i^ x 2^ mm. to 5J x 34; mm. 



(2.) Lake Rotoiti (Stat. 18 — Dredged with weeds in 6 ft.). — 

 Seventeen specimens of rather uniform size and shape, covered 

 with a greenish-black coating. There are five rounded smooth 

 whorls ; only one specimen shows traces of bristles on the upper 

 whorls. The peritreme is sometimes, not always, black. A few 

 specimens are approaching corolla, being more ventricose than 

 the subspecies. The dimensions vary from 5 x3 mm. to 6 x4 mm- 



(3.) Lake Rotoiti (Stat. 18f — Dredged with weeds in 6 ft.). — 

 Sixteen specimens, all " dead shells." Very much the same as 

 the preceding. Dimensions range from 5x3 mm. to 5 \ x 3 \ mm. 



(4.) Lake Taupo (Stat. 6— Dredged in 25 ft. to 420 ft.).— 

 Many specimens, all light-horn colour, about two-thirds with 

 smooth rounded whorls, the others with a carina above the 

 periphery on which very short spines are situated, having a 

 broad base, from which two to three separate spines arise. This 

 is a feature met with in specimens of P. corolla from Lake Kanieri, 

 South Island. The variability of the arrangement of the spines 

 is just as great as in P. badia. The pullus is mostly brown and 

 shining. The first two and a half whorls are always convex, 

 never shouldered. The peritreme is continuous and brown. 

 Young specimens have sometimes the body-whorl angled below 

 the periphery, but no chordate carina is present. The size is 

 very variable, ranging from 5x3 mm. with six whorls to 8| x 

 5 mm. with seven whorls. 



(5.) Lake Taupo (Stat. 6f— Dredged in 25 ft. to 420 ft.).— 



About two dozen specimens, showing the same characters as 



those of Stat. 6. The dimensions vary from 5| x 3 mm. to 



8Jx5 mm., with six and seven whorls respectively. 



' (6.) Lake Taupo (Stat. 16f— Dredged in 280 ft. and 320 ft., 



