418 TERRESTRIAL AIR-BREATHING MOLLUSKS. 



masses are very numerous in the latitude of Boston, in the warm days of June. 

 The eggs are oval and transparent. 



This is not the S. ovalis of Say. That shell having been found identical 

 with 5. obliqua, Dr. Gould proposes retaining the name ovalis for this species. 



Mr. Gwynn Jeffreys refers the species to S.elegans, Riss) (Ann. and Mag. 

 N. H., 1872, 246). 



Jaw (according to Morse) arcuate, ends blunt ; anterior surface with strong 

 vertical furrows, which modify the concave inargin. 



A specimen examined by me had a jaw with a smooth anterior surface and 

 well-developed median projection. 



Mr. Morse gives 80 rows of 40 1 40 teeth on the lingual membrane. A 

 membrane examined by me (PI. X. Fig. M) had over 60 1 60 teeth. 



Succinea Higginsi, BLAND. 



Shell depressed-oval, thin, obliquely striated, pellucid, somewhat shining, 

 pale horn-colored ; spire short, obtuse ; suture deep ; whorls 

 ' 3, convex, the last rather depressed ; the columella scarcely 



arched, above conspicuously plicate ; aperture angularly oval, 

 frequently armed with a small, oblique, white tooth on the 

 parietal wall ; peristome simple, regularly arcuate. Length 

 1 5, diameter 7 mill. ; aperture, 1 1 mill. long. 



S. Higginsi. 



Succinea ffigginsi, BLAND, Am. Journ. Conch., II. 373, PI. 

 XVII. Fig. 24 (1866). TRYON, Am. Journ. Conch., II. 237 (1866). W. G. 

 BINNEY, L. & Fr.-W. Sh., I. 258 (1869). 



Put-in-Bay Island, Lake Erie ; a species of the Northern Region. 



Animal not observed. 



This species is allied to S. Salleana, Pfr., S. Haydeni, Binn., and especially to 

 S. ovalis, Gould, not Say. Compared with the latter, the last whorl is less 

 convex, the aperture is more angular above, the columella less arcuate, and 

 more distinctly plicate. 



The measurements given are of one of the largest specimens. This is the 

 only North American species in which I have noticed the parietal tooth men- 

 tioned in the description. Three of my specimens have this tooth, it is 

 lamelliform, about 1 mill, in length at the base, the pointed apex having an ele- 

 vation of about mill. (Bland.) 



Succinea Concordialis, GOULD. 

 Vol. III. PI. LXVIL a, Fig. 2. 



Shell obliquely ovate, elongate, reflexed, apex acute, thin but firm, transpar- 

 ent, shining, feebly striated lengthwise and spirally, color pale honey-yellow, 

 with the tip ruddy ; whorls 3 and somewhat more, very oblique, the two upper- 

 most very small, outer whorl somewhat compressed above the middle ; suture 



