Dentition of Pulmonata. 40 



rant form of centrals and laterals, as Bulimulus aurislejporis, 

 (Mai. Blatt., XV, pi. v, fig. 8). In less degree are the 

 laterals modified from the usual Helidnm type in Simpulopsis 

 sulculosa (ib. fig. 10) as to the cutting points, and in the 

 same particular in Bulimus Peruvianus (Proc. Ac. Nat. Sc. 

 Phila., 1874, pi. v, fig. 2). No doubt future research will 

 bring to light a complete series of teeth in land shells, show- 

 ino- a o-radual modification in difi'erent directions of the nor- 

 mal tricuspid and bicuspid type. 



There seem no peculiar characters to the respiratory, digestive and 

 nervous system of the animal. The genitalia are figured on plate IV, fig. 

 F. The external orifice is behind the right eyepeduncle. The testicle (1) 

 is as usual in the Heliciiice embedded in the lobe of the liver occupying 

 the extreme apex of the spire of the shell; it is coirtposed of fasciculi of 

 short, stout, blunt cceca. The epididymis (2) is short, convoluted as 

 usual. The accessoi-y gland (3) is on a short threadlike peduncle. The 

 ovary (11) is very large, tongue shaped, lobulated above and decidedly 

 spongelike in its division on its concave side. The oviduct (8) is long, 

 narrow, convoluted. The genital bladder (9) is large and oval, on a long 

 duct (IG) which in its natural position is adherent to the oviduct in its 

 entire length : it is much larger in its lower third, equalling the stout 

 vagina, near whose middle it enters ; below this point the vagina becomes 

 very stout. The penis is cylindrical, about as long as the vagina, tapering 

 rather abruptly to its apex, where is inserted a long, delicate, retractor 

 muscle (6), which resembles a flagollum. The vas deferens (7) enters 

 the penis on its side, near its summit. There are no accessory organs. 

 The penis (5) does not appear to enter a common duct of male and female 

 organs, but to have a separate opening of its own. 



The general arrangement of the genitalia is like that of 0. unclatus, 

 (see this paper), 0. longus and iostomus (Fischer and Crosse), Liguiis 

 fasciatus (Leidy), and L. virgineus, see below. The last four, however, 

 have a single raultifld vesicle, which I failed to detect in 0. galUna-sul- 

 tana; and from them all there is ample specific difi"erence in the size of the 

 ovary, the shape and size of the penis sac, and the size of the duct of the 

 genital bladder, near its base. 



It may fairly be assumed that no generic difference exists between the 

 genitalia of Orthalims and Liguus. 



These remarks are suggested by the treatment of Liguus 

 fasciatus by Messrs. Fischer and Crosse (Moll. Mex. et 

 Guat.). On account of the resemblance in dentition to 

 the species of Orthalicus known to them rather than to the 



