NATURAL SCIENCES OF PHILADELPHIA. 249 



which about 25 may be called laterals, but the change to margi- 

 nals is hardly marked, these last differing only in being smaller, 

 in having a more square base of attachment, and in having more 

 obtuse and more proportionally developed cutting points ; there 

 is no splitting of the inner cutting point of the marginals. The 

 centrals have subobsolete side cusps, but decided side cutting 

 points ; the central cusp is short and stout, the base of attach- 

 ment has greatly expanded lower lateral angles. Laterals like 

 the centrals, but unsymmetrical as usual. 



The dentition of this species resembles that of provisoria and 

 notabilis of the same subgenus. 



The genitalia are figured on pi. XIX., fig. 3. The penis sac 

 (p. s.) is stout, rounded, with long, pointed apex ; the vas deferens 

 (v. d.) enters it below the apex ; the retractor muscle (r.) is in- 

 serted in the vas deferens just before it enters the penis sac. 

 The genital bladder (gr.fi.) is short, cylindrical, with blunt end; 

 its duct is short and small. The penis sac enters the vagina 

 opposite the entrance of the genital bladder. 



Helix {Carocolus) sagemon, Beck. 



Cuba. Mr. Arango to Mr. T. Bland. 



Jaw high, arcuate, ends rapidly but slightly attenuated, blunt ; 

 cutting margin with broad, blunt, median projection ; no anterior 

 ribs. 



Lingual membrane (pi. XXL, fig. 4) very long and narrow, with 

 36 l 36 teeth, the transverse rows of teeth being unusually ob- 

 lique. The change from laterals to marginals is so gradual that it 

 is difficult to say how many of the former there are. Centrals with 

 base of attachment long, constricted at the middle, expanded 

 above and with greatly produced lower lateral expansions ; reflec- 

 tion large, with obsolete side cusps and no side cutting points, and 

 with a very broad, short median cusp, bearing a short, widely 

 expanded, square cutting edge (as it cannot be called a point).- 

 Laterals like the centrals, but unsymmetrical as usual, and with 

 an unsymmetrical cutting edge larger than in the central tooth. 

 The cutting edge becomes more developed as the teeth pass off 

 laterally, in proportion to the base of attachment and the cusp 

 also. Thus the marginals become formed without any splitting 

 of the inner cutting point, or any development of a side cusp and. 

 17 



