202 



AMERICAN JOURNAL 



NOTES ON LINGUAL DENTITION. 



BY W. G. BINNEY AND THOMAS BLAND. 



No. 2. 



In studying the lingual membranes here described we have 

 been greatly assisted by our friend Mr. Sam. Powel, of New- 

 port, R. I. Many of the figures are drawn from photographs 

 taken directly from the microscope by Mr. Powel. 



Glandina rosea, Per. 



The specimen from which was extracted the lingual membrane 

 here described was received from Mr. McNeil, who collected it in 

 Nicaragua. 



Lingual membrane long and narrow, with 36 rows of 25 — 1 — 

 25 teeth. Rows very oblique, running rapidly downwards and 

 outwards from the centre for about two-thirds of their length, 

 then curving upwards to the extreme margin. Centrals long, 

 narrow, slightly incurved at the sides, emarginate at top, rounded 

 at base, and bearing a short, blunt, stout, apical projection. 

 Laterals entirely wanting. Uncini separated, thorn-shaped, 

 their apices springing from a sheath which rests upon a long, 

 narrow base ; this base, seen from below, has 

 in shape a strong resemblance to the sole of a 

 boot. The uncini increase in size as they pass 

 off laterally from the central line for about 

 two-thirds of the way ; they then commence 

 rapidly to decrease in size ; their sharp, thorn- 

 like apices, however, are larger in proportion 

 to the base of the teeth as they pass towards 

 the outward margin. 



The figure shows one central and one of the 

 uncini as seen from below. 



Our figure was obtained in the same manner 

 as that of Megalomastoma hituberculatu7n. See 

 p. 213. 



This membrane is interesting in showing the 

 presence of a well developed central line of teeth. 



Fis. 1. 



Gl. rosea. 



