7<S4 SCIENTIFIC RECORD FOR 1885. 



the North American species are referred by Mr. Binney to the genus 

 Limax and are seven in number. 



VIII. The Arionida; include forms which have the jaw entire and 

 transversely ribbed ; the teeth of three types, (1) a wide central ob- 

 scurely tricuspid; (2) lateral, " like the centrals but asymmetrical by the 

 suppression of the inner lower lateral expansion of the base of attach- 

 ment," and (3) marginals quadrate, low and wide; the mantle anterior, 

 small and shield-like, and the shell represented by a small flat plate or 

 granules. The North American species are referred to two genera, 

 Arion with two species (one introduced from Europe) and Arioiiraax 

 with five. These species are interposed between genera of the Helicidte 

 by Mr. Binney. 



IX. The PhilomycidsB have a "jaw with or without anterior ribs, 

 and median projection or cutting edge," teeth distinguishable into cen- 

 tral, lateral, and marginal; a mantle covering the whole body, and the 

 shell entirely suppressed. Four species are found within our Mmits, all 

 of which are referred to the genera Tebeunophorus, although there are 

 two quite distinct forms which seem to have been confounded in it. 

 The names used by Professor Morse are Tebeunophorus and Pallifera. 



X. The Orthalicidte are forms which have a peculiar jaw in that it 

 is " thick, solid, composed of a median triangular piece, with base cor- 

 responding to upper margin of jaw, and near the apex of which con- 

 verge on either side oblique imbricated plates, tree below, adherent 

 above." The teeth are distinguished into " central and lateral teeth with 

 quadrangular base, with central cusp more or less obtuse, generally very 

 much expanded, with rudimentary side cusps" and "marginal teeth 

 quadrate, of same tyi)e ; " the mantle is posterior and included, and 

 the shell spiral and turreted. Two species are found in Florida belong- 

 ing to the genera Orthalicus and Liguus. 



XI. The Punctidse include forms with the "jaw low, wide, slightly 

 arcuate, with blunt, squarely truncated ends, "disintegrated into many" 

 (about sixteen) " separate pieces, each higher than wide, with small 

 overlapping edges ; " the teeth are quite peculiar (but most like those 

 of the Auriculidae) and represented only by centrals and laterals hav- 

 ing bases of attachment longer than wide, expanded below and squarely 

 truncated, and free portions narrowed and reflected ; " the mantle is 

 submediau, and the shell heliciform. Not more than one species is cer- 

 tainly known within our limits. It is the Helix minutissima or Punc- 

 tum minutissimum of most American authors, but it is regarded by Mr. 

 Binney as being identical with a European species and called by him 

 Microphysa pygmaea. 



XII. The Succiniidse have a jaw surmounted by an accessory quad- 

 rangular plate, teeth differentiated into (1) a central tricuspid, (2) lat- 

 eral which are tricuspid or bicuspid, and (3) marginal of a quadrate form 

 "with narrow base, multicuspid reflection, serrate by the splitting of 

 the inner cusp into numerous denticles;" mantle more or less included 



