May, 1846.] 67 



If this species from Yucatan be the G. obtusa, Dr. Pfeiffer has 

 described a young shell, the dimensions of the Nicaragua shell 

 being, length 9| lines, diameter 5 lines ; last whorl rather longer 

 than spire of the Yucatan shell ; d. 14 lines ; diameter 5^ lines ; 

 aperture 5J lines. The character of the surface in Gr. obtusa is 

 not noticed. The specimens from Yucatan are minutely striated 

 longitudinally,thestria3 the strongest near the sutures and becoming 

 "weaker towards the aperture ; these striae are crossed by very 

 minute revolving lines, giving the shell under a good glass a 

 slightly granular aspect. The Gr. obtusa is described as " ovata 

 utrinque attenuata ;" these adult shells have the two last whorls 

 almost cylindrical. 



See plate 1, fig. 33, in No. 1. 



Should it prove to be distinct from the Nicaragua species, I 

 would propose the name of 



G-landina (Achatina) cylindracea. Testa sub-cylindracea, apice 

 obtusa, solidula, pellucida, pallidissime carnea, longitudinaliter 

 tenue striata, striis decussatis lineis exilissimis, anfractibus 7, vix 

 convexiusculis ; sutura crenulata, apertura mediocre, spira bre- 

 viore ; columella basi contorta, et subito truncata ; peristomate 

 simplici ; marginibus callo tenuissimo vix junctis ; dextro medio 

 non dilatato. 



Length 1 *1 diameter i!L , length of aperture 51. 



100 100 ' & r 100 



Shell subcylindrical, apex obtuse, moderately thick, pellucid, 

 very pale flesh color, finely striated longitudinally, the striae 

 crossed by very minute lines ; whorls 7, slightly convex ; suture 

 crenulate ; aperture moderate, shorter than the spire ; columella 

 curved at the base, and suddenly truncated ; outer lip thin ; not 

 dilated in the middle; inner lip scarcely covered by a slight callus. 



The Monthly Report of the Corresponding Secretary was read 

 and adopted. 



On motion of Prof. Johnson : Resolved, That a copy of Har- 

 lan's Med. and Phys. Researches be presented to the Essex Co. 



(Mass.) Nat, Hist. Society. 



