3G4 



TKRRESTRIAL AIR-BREATHING MOLLUSKS. 



Fig. 245. 



Helix reticulata (Pfeiffer). 



Fig. 246. 



Arionta ramentosa, Gould. 



Shell umbilicate, depressed-globose, solid, obli<|iiely striated, and marked 



with oblong, somewhat regular granulations 

 formed by stria; descending towards the an- 

 terior part ; yellowish with one revolving 

 reddish band ; spire shortly conic ; whorls 5i, 

 somewhat convex, the last broad, rounded, 

 not falling in front ; umbilicus narrow, not 

 pervious ; aperture diagonal, roundly lunate ; 

 peristome white, thickened, its ends not converging, the right scarcely ex- 

 panded, the columellar sloping, dilated above and reflected. Greater diam- 

 eter 22, lesser 18 mill. ; height, 11^ mill. 



Helix ramentosa, Gould, Proc. Best. Soc. Nat. Hist., VI. 11 (1845) ; Terr. Moll. 



U. S., III. 12. — Pfeiffer, Men. Hel. Viv., IV. 349.— W. G. Binney, Terr. 



Moll., IV. 13. 

 Aglaja ramentosa, Tkyon, Am. Journ. Conch., II. 314 (1862). 

 Helix Parkcri, Tkyon, 1. c, III. 105. 

 Helix reticulata, Pfeiffer, Mai. Blatt., 1857, 87 ; Men. Hel. Viv., IV. 270 ; 



Nov. Conch., I. 120, PI. XXXIV. Fig. 47.— W. G. Binney, Terr. Moll., IV. 



12 ; L. & Fr.-W. Sh. I. 169, Fig. 294 (1869). 

 Helix Bridgesii, Newcomb, Proc. Cal. Acad. Nat. Sei., II. 



91 (1861). 

 Aglaja Bridgesii, Tryon, Am. Journ. Conch., II. 313 



(1866). 



Napa County, to Santa Clara County, California, in the 

 California Region. 



Fio-. 245 is a fac-simile of one of Pfeiffer's. 



Specimens of Helix Bridgesi received from Dr. New- 

 comb resemble forms of A. ramentosa so closely that I be- 

 lieve the two to be identical. An authentic specimen, 

 loaned by Dr. Newcomb, is figured here. The name 

 Parkeri was suggested, as Bridgesi was preoccupied in 

 the genus Helix. 



The above description is of the form known as reticu- 

 lata. The original description of ramentosa here follows, 

 doubt of the identity of the two forms. 



Shell perforate, suborbicular, depressed, thin, reddish, with a smoky, white- 

 margined band revolving at the periphery ; granulated with incremental lines 

 and equally oblique, decussating furrows ; whorls 5|, rather convex, the last 

 obtusely angulated ; suture deeply impressed ; aperture obliquely oblong-ovate ; 

 peritreme acute behind, white, decidedly reflected towards the umbilicus ; throat 

 reddish. Greater diameter, 20 mill. ; height, 1 2 mill. 



Jaw stout, strongly arcuate, dark horn-color, transversely striate ; ends but 



Helix Bridgesi. 



There can be no 



