THE NAUTILUS. 



G. lasmodon Phill. That so good a conchologist as Shuttleworth 

 should have described a known species is readily explicable in this 

 case; " H. lasmodon'' having been described but a short time before 

 in the proceedings of a society probably not in Shuttleworth.' 3 posses- 

 sion, it had not been figured and was not contained in any general work 

 on the shells of America. However this may be, so good a diagnosti- 

 cian as Shuttleworth could have used the words, u late et perspective 

 umbilicata " of no other species of the region, and the rest of the de- 

 scription,* as well as the comparison with Patula, agrees excellently 

 with lasmodon. This conclusion will remove macilenta from the list 

 of valid species and place it under latnwlon as a synonym. 



The gularis group of Gastrodonta is a peculiarly perplexing one. 

 Both gularis and cuspidata were originally described as imperforate ', 

 butboth have perforate forms also. G. gularis was described from Ohio 

 and I will be most grateful to anyone who has Ohio specimens, for a 

 few. Shell out, brethren ! Mr. Vanatta, who has recently overhauld 

 the series in the Ac id 3 my collection, informs ni3 that he finds great diffi- 

 culty in separating G. collisella from gularis, and it seems likely that 

 that form should be ranked as a variety of gularis rather than a dis- 

 tinct species. He finds, too, that there is a narrowly umbilicated var- 

 iety (already noticed by Biuney) and another with notably excavated 

 base, consequently straight baso-columellar lip, and more or less defi- 

 cient internal teeth. This was named by Mr. A. D. Brown in his 

 collection (now in coll. A. N. S. P.); but pending a thorough exam- 

 ination of the gularis group, it is scarcely fair to worry a long-suf- 

 fering generation of conchologists with any names for these local races. 

 The genitalia of the various forms should be examined. 

 Polygyra postelliana sub3lausa, u. v. 



Differs from P. postelliana in the greater development of all the 

 oral obstructions. The parietal process enters more deeply ; the upper 

 lip-tooth is more deeply placed, more strongly hooked than usual in 

 the typical form, and the apertural orifice decidedly narrower through- 

 out, shaped like an interrogation mark (?) without the terminal dot. 

 Surface regularly rib-striate, below as well as above. Whorls 5 to 6. 

 Alt. 5.7, greatest diam. 10 m n. \lt. 5, greatest diam. 9 mm. 



Bauldingsville; Baldwin, Baker county, and Imri, Hamilton county, 

 Florida. 



A smaller form of this variety, smoother below, occurring in Volu- 



* A slightly inaccurate translation is given by Binney in Manual of Ameri- 

 can Land Shells, p. 227. 



