178 CALLIONEPION. 



Genitalia (pi. 31, figs. 3, 7) without accessory organs; 

 atrium short; the penis large, elongate, the vas deferens in- 

 serted at its apex, beyond which a hollow tube or sack (fig.7, 

 x.) of unknown nature extends, terminating in a short re- 

 tractor muscle; talon (t.) large, composed of a thick curved 

 basal portion and a slightly longer, narrow terminal part. 

 The vagina is short; spermatheca globular, lodged near the 

 heart, its duct long and slender ; free oviduct very short, the 

 convoluted portion unusually long; albumen gland well de- 

 veloped. Hermaphrodite duct moderately convoluted. 



Probably oviparous, the young shell when hatched about 

 one-tenth the length and less than one-third the diameter of 

 the adult shell. 



The right eye-retractor muscle passes between $ an d 9 

 branches of genital system; the penis retractor muscle is in- 

 serted upon the diaphragm. 



The jaw is lost, and the radula obtained is frayed at the 

 edges, so that the number of teeth in a transverse row cannot 

 be stated, but it was probably not over fifty. The rhachis 

 consists of well-developed teeth, fully as wide as the laterals, 

 with square basal plate and tricuspid reflection, the middle 

 cusp large, about as long as the basal plate; the side cusps 

 small. In the lateral teeth an inner cusp is absent. Mar- 

 ginals similar, with oblique mesocone, acute small ectocone 

 and short basal plate (pi. 31, figs. 8, 9). 



Affinities of Callionepion. I formerly placed this genus 

 as an aberrant group among the Stenogyroid Achatinidce; 

 but further consideration inclines me to think it more nearly 

 related to Megaspira, though no close relationship can be 

 claimed, and the question of its affinities is still an open one. 

 The peculiar disparity between the sculpture of the nepionic 

 and post-nepionic whorls of the shell (when not obscured by 

 erosion), the free, expanded edge of the columellar lip, and 

 the sharp though small median fold on the columella, are 

 characters sundering Callionepion from American Steno- 

 gyroid genera. 



The vagina is much shorter than in Rumina (where it 

 equals the length of the spermatheca duct), and the duct of 



