232 PROCEEDINGS OF THE ACADEMY OP 



Siwciyiea lineata (pi. XV., fig. 11) has 26 — 1 — 26 teeth, with 4 

 perfect laterals, but the transition to marginals is very gradual. 

 The teeth have a very broad base of attachment, and very slender, 

 sharp cutting points. 



Succinea avara (pi. XY., fig. 3) has 21 — 1 — 21 teeth, with about 

 8 perfect laterals. Morse counted 19 — 1 — 19 teeth. 



Succinea obliqua (pi. XV., fig. 4) has 43 — 1 — 43 teeth, with 10 

 perfect laterals. 



Succinea Totteniana is said by Morse, whose figure is given in 

 L.and Frw. Shells, I., p. 267, to have 100 rows of 33—1—33 teeth. 

 The bases of attachment are very narrow. 



Succinea campestris (pi. XV., fig. 10) has 18 — 1 — 18 teeth, 

 with about 10 perfect laterals. Morse gives 50 rows of 30 — 1 — 30. 

 The central tooth has a peculiarly narrow base of attachment, 

 and a very greatly developed median cusp, the side cusps being 

 subobsolete. 



Succinea Nuttalliana (fig. 74). Teeth 19 — 1 — 19. 



Succinea effusa (pi. XV., fig. 6) has 15—1—15 teetb, with 10 

 perfect laterals. 



Succinea Stretchiana (pi. XX., fig. 7). 16—1—16. 8 laterals. 



I have had no opportunity of examining the other species of 

 Succinea found within our limits. 



Family VERONICELLID^. 



Genus VERONICELLA Blainv. 



Jaw (fig. 75) low, wide, thick, slightly arcuate ; ends but little 



attenuated, blunt; cutting margin without median 



Fig. 75. projection ; anterior surface with numerous, stout? 



^5MI^ crowded ribs, denticulating either margin, 24 in V. 



Jaw of Floridana. 



veroniceiia Lingual membrane, as seen in fig. 76, is arranged 



Fioridana. ^^ ^^^^^ -^ ^^^ Helicinse^ the transverse rows being 



