NOTES ON THE STENOGYRIN^E. XI 



The radula (pi. 51, fig. 10, Z. insularis) has 19,1,19 teeth in 

 Z . pullus, 26,1,26 in insularis. The middle tooth is very nar- 

 row, with a single ovate cusp. Laterals with a long mesocone 

 and small ectocone, but no trace of an inner cusp. On the 

 marginal teeth both cusps become bifid. The absence of an 

 inner cusp on the side teeth is a peculiarity Zootecus shares 

 with Riebeckia. 



The genus Cylindrogyra Repelin (Annales Musee d'Hist. 

 Nat. de Marseille, vii, 1902, 'p. 63) of the Cenomanien of cen- 

 tral France, may possibly belong to this phylum, but its posi- 

 tion is very doubtful. Pyrgulina Matheron, t. c., p. 16, is a 

 synonym of Cylindrogyra. The genus Nisopsis Matheron 

 (t. c., pp. 16, 64) is placed near Cylindrogyra by Repelin. 

 It is conic- turrite and umbilicate, and to me has not the ap- 

 pearance of a Stenogyroid snail. 



V. Obeliscus phylum. 



Mainly large, turrite or cylindric shells, imperforate or 

 nearly so, and in adults with the columella continuous with 

 the basal lip or rarely weakly truncate, though the young or 

 embryonic stage often has a truncate achatinoid columella. 

 Most or all of the species are viviparous. Radula, so far as 

 known, with unicuspid middle and tricuspid side teeth. The 

 following genera belong here : 



America. Africa. S. E. Asia. 



Neobeliscus. 



Obeliscus. Euonyma. Tortaxis. 



Rhodea. 

 ? Synapterpes. 



So far as we know, there is little reason to separate Obe- 

 liscus, Euonyma and Tortaxis generically ; yet their wide geo- 

 graphic separation makes such segregation useful, pending 

 an investigation of the soft anatomy. 



The anatomy of Neobeliscus has been described in some de- 

 tail in the text. The teeth of Obeliscus are described below. 

 Nothing is known of the soft parts of the other genera. 



The radula of Obeliscus obeliscus (pi. 51, fig. 9) resembles 



