E. B. Meek on Acteonide. 93 
Subgenus Evrryoma, Meek 
Shell like Avellana in form ; aperture very narrow, arcuate; columella 
large obtuse teeth or tubercles, at the base within. Surface with com- 
8. 
Auricula decurtata, Sowerby,” (Avellana, Zekeli). Also in- 
s.) 
Srorton 6, 
Genus APTYCHA, Meek, 
Shell oval; spire moderate; body-whorl rather large. Aperture nar- 
d 
tow subovate, rounded below, and acutely angular above; outer li 
smooth within, inner lip callous, particularly above, but destitute of any 
folds on the columella, so characteristic of that section of the subfamily, 
It therefore bears exactly the same relation to those genera, that Acteon- 
tna bears to Acteon, Tornatellea, Solidula, d&sc., in the subfamily Acte- 
onine, 
ons from an elevated to a depressed or sunken spire, are so 
oe, that within a considerable range of limits, it cannot 
the thickness or thinness of the shell, &c., and the various combi- 
nations of these and other characters, sometimes individually of 
subfamily or sectional value. 
Teady been stated. it will be remembered that the shells of 
many of the warty tales Boom a constant tendency to shade off 
“ Trans, Geol, Soe. Lond, iii, pl. 88, fig. 10. _* Ibid, 2d ser. vol. vii, pl xi, f. 24. 
