Jaw and Lingual Dentition of Pubnonata. 187 



Lingual membrane long and narrow (pi. xvi, fig. B.). Teeth as 

 usual in the Helkinaz. The change from laterals to marginals is very- 

 gradual, the latter being but a modification of the former, with two cut- 

 ting points, the inner the longer. Thus it appears that this species in its 

 dentition agrees with B. cinnamomeo-lineatus, pallidior, chrysalis, deal- 

 batus, Guadalupensis, alternants, sporadicus, sulutus, sepulcralis, durus, 

 Peruvianns, rhodolarynx, and not with laticinctus, Bahamensis, auris-leporis, 

 papyraceus, Jonasi, membranaceous, trigonostomus, flavidus, virginalis, con- 

 vexus, Vincentiuus, Lobbi, alter nans, multifasciatus, primularis (see Ann. 

 Lye. N. II. of N. Y., XI, 34 et seqq.). 



Teeth 30-1-30 with about ten laterals. The outer cutting point of the 

 marginals is sometimes bifid. 



Cylindrella Poeyana, Orb. 

 Key West. Mr. W. W. Calkins. 



Jaw as usual in the genus, with about 40 delicate ribs. 



Lingual membrane long and narrow (pi. xv, fig. F). Teeth 14-1-14 

 of the same type as I have already shown to exist in this subgenus Gon- 

 gylostoma (see C. eleyans, Pfr. Proc. Phil. Ac. Nat. Sc., 1875, pi. xx, fig. 6). 



Cylindrella ornata, Guudl. (Gongylostoma). 

 Cuba. Cabinet of Mr. Bland. 



Jaw not observed. 



Lingual membrane with 18-1-18 teeth, of which three only are well 

 formed laterals, the change to marginals being very gradual. The type 

 of dentition is the same as I have described in C. Poeyana (see above). 

 It will be noticed in my figure F of plate xv, that there is a slender, 

 simple, upper prolongation or pedicle above the inner, palmate cutting 

 edge, as well as the pedicle on which the outer cutting edge rests. This 

 is the case also in C. eleyans and C. Poeyana, and may, therefore, be con- 

 sidered characteristic of the sectiou Gongylosioma. 



Amphibulima Rawsonis, Bland in litt. 



Governor Rawson to Mr. T. Bland. Island of Montscrrat, 

 between Nevis and Guadeloupe. 



Plate xiii, fig. C, represents the genital system. There are no acces- 

 sory organs. 



The jaw is as usual in the genus (see Proc. Phila. Ac. Nat. Sc, 1S74, 

 pi. viii, fig. 2, for that of A. rubescens). About 33 ribs, those at the 

 upper centre of the jaw running obliquely and meeting or ending before 

 reaching the lower margin. 

 November, 1875. 14 Ann. Lyc. Nat. Hist., Vol. xi. 



