350 TERRESTRIAL AIR-BREATHING MOLLUSKS. 



AGLAIA, ALBERS. 



Animal heliciform, as in Patula ; mantle subcentral. 



Shell umbilicate, orbicularly convex, striatulate, banded ; whorls 4 J - 6, the 

 last deeply deflexed in front ; aperture lunate-ovate, very oblique ; peristome 

 thickened, expansively reflexed, white, its margins approaching, that of the 

 columellar dilated, reflexed, free, partially covering the umbilicus. 



Within our limits this genus is found only in the Pacific Region* A few 

 Mexican and South American species are also known. 



Jaw thick, high, arched, ends but little attenuated, blunt; cutting edge with- 

 out median projection ; anterior surface with stout, separated 

 ribs, denticulating either margin, from 5 to 9 in A. infumata 

 (Fig. 234), about 6 in Jidetis. The other American species, //. 

 Hillebrandi, I have not examined. 



Linual membrane lon and narrow. That of Hillebrandi 



Jaw of D0 examined, those of infumata and fidelis agreeing in their 



A. infumata. J 



general characters. The centrals have a base of attachment 

 longer than wide, with incurved lower margin and expanded lower lateral 

 angles ; upper margin broadly reflected ; reflection short, stout, with no side 

 cusps or cutting points, but a very stout, short median cusp, bearing a short 

 cutting point. Laterals like the centrals, but asymmetrical by the base of 

 attachment wanting the inner, lower lateral expansion ; it is, however, unusu- 

 ally developed on its inner side margin : first marginals differing from the 

 laterals by the equalling of the reflection and base of attachment, the lesser 

 development of the cusp, and greater development of the cutting point, 

 which is bluntly bifid, the inner division the smaller. On some of the first 

 marginals of infumata there is a small side cutting point. Marginals low, 

 wide, the reflection equalling the base of attachment, and bearing one long, 

 oblique, wide, bifid cutting point, the inner division the smaller, and one or 

 two short, sharp, side cutting points. There is great variation in the cutting 

 points. 



A comparison of the two figures will show a longer base of attachment in 

 fidelis, with a line of reinforcement or duplication to its upper margin. As 

 with all species, there is much variation in the length of the cutting point, in 

 centrals and laterals, and their arrangement and development in the marginals. 



Of the dentition of the other species of Aglaia foreign to our limits but little 

 is known. A. Ghiesbreghti (see Moll. Mex. et Guat.) has very dissimilar teeth, 

 especially the marginals. A. semiclausa (Malk. Blatt. XV. PL IV. Fig. 4) 

 also differs in its dentition. The jaws of these species agree with those of 

 infumata and Jidelis. 



Aglaia fidelis, GRAY. 

 Vol. III. PL XH.X 



Shell umbilicated, orbicularly subconoid ; epidermis light-yellow or brownish 

 on the upper surface, with a black or chestnut-colored revolving band visible 



