OF CONCHOLOGY. 



203 



It has been affirmed that the genua Glandina has no central 

 line. M. Crosse has shown its existence in the European spe- 

 cies. Mr. Morse has detected it in Glandina truncata and G. 

 Albersi. (See Land and Fresh Water Shells of North America, 

 Part I.) 



LiMAX MAXIMUS, Lin. 



The specimen figured in Invertebrata of Massachusetts, second 

 edition, page 408, furnished the jaw and lingual membrane here 

 described. 



Jaw long, narrow, arcuate, strongly striated both vertically 

 and transversely ; ends attenuated ; cutting edge with a promi- 

 nent median projection. 



The lingual membrane agrees perfectly with that of the allied 

 species L. Jiavus, figured in Land and Fresh Water Shells of 

 North America, Part I, p. 63, fig. 105. 



Several individuals of Limax maximus, ke^t in confinement 

 at this time, have been guilty of cannabalism. They devoured 

 more than half of one of their kind before the crime was dig- 

 covered. 



Helix tumida, Pfr. 



We have already (Annals 

 N. y. Lye, vol. ix, p. 288) 

 described the lingual dentition 

 and the jaw of Helix tumida. 

 An opportunity has since oc- 

 curred to examine other speci- 

 mens of the same species. 

 Finding the character of the 

 jaw confirmed by these later 

 examinations, we have given 

 here a figure of the jaw. We 

 described the jaw as long, nar- 

 row, slightly arched, blunt at 

 ends, with a slight, broad, 

 median projection; there is a long, narrow, conical projection 

 springing upwards from about the centre of the anterior surface 

 of the jaw, of the same color, material, and consistency as the 

 jaw itself; this is not the muscular attachment which often ad- 

 heres to the jaw after it has been extracted ; jaw with delicate, 

 distant, longitudinal striae. To the above description we must 

 add that the longitudinal striae pass uninterruptedly from the 

 jaw into this projection, showing the same continuity of struc- 

 ture. 



The muscular attachment often adhering to the extracted jaw 



H. tumida. 



