JVew Land Shells from Costa Mica. 261 



are bifid by having the side spur often found on the side mar- 

 ginals in this genus. The 13th, 14th, and 15th teeth form the 

 transition into the marginals. 



Grlandina (a large species not yet identified). 

 The lingual membrane is as usual in the genus. There are 

 33-1-33 teeth. 



Helix (a small unidentified species). 



Jaw not observed. 



Lingual membrane (plate xi, fig. G), long and narrow. Teeth 

 15-1-15. Centrals with a base of attachment longer than wide, 

 with lower lateral expansions ; reflection large, decidedly tricuspid, 

 each cusp surmounted by a cutting point. Laterals like the centrals, but 

 asymmetrical and consequently bicuspid.' Marginals low, wide, irregu- 

 larly denticulated or serrate, the inner three cutting points being longer 

 than the outer ones, of which there are several. 



Locality, Upper Tirili River. 



Tebennophorus. 



There are several drawings of slugs of this genus, apparently 

 all referable to one species. It may be that described by 

 Morch (Mai. Blatt., VI, 109) as Costaricensis. 



Several of these figures are given in plate xi, fig. M. 



The jaw of this is strongly arched, of equal width to its 

 blunt extremities. There are subobsolete anterior ribs about 

 the centre of the jaw, the ends of five of which denticulate 

 the cutting margin. 



The lingual dentition is figured on plate xi, fig. N. There 

 are about 28-1-28 teeth. The centrals have a long base of 

 attachment, with a strong line of reinforcement running par- 

 allel to its margin at the lower edge and for a short distance 

 at the sides. The reflection is small, and bears a short, stout 

 median cusp, and small stout side cusps, all three cusps bear- 

 ing short, stout cutting points. The lateral teeth are like the 

 centrals, but asymmetrical by the suppression of the inner 

 cusp and cutting point and the inner lower expansion of the 

 base of attachment. The marginals are but a modification of 

 t he laterals, the inner cutting point not becoming bifid, though 



