PILSBRY: NON-MARINE MOLLUSCA OF PATAGONIA. 531 



A. c. bonceriensis Strobel, Doering, Informe Oficial de la Comision cien- 

 tifica agregada al estado mayor general de la Expedition al Rio 

 Negro, bajo las ordenes del General D. Julio A. Roca, Zoologia, p. 

 71, 1881. 

 Rio Negro near the mouth of the Rio Neuquen (Roca Exped.). 



Family CHILINID& Ball. 



Chilinidce Ball, Annals of the Lyceum of Natural History of New York, 

 IX, 1870, p. 357. 



CHILINA Gray. 



Chilina Gray, Specilegia Zoologica, p. 5, July i, 1828 (for Auricula fluc- 



tnosa Gray). 

 Dombeia d'Orbigny, Voyage dans 1'Amerique Meridionale, Mollusques, 



planche 43 (1843?). 

 Duplicaria Rafinesque, Atlantic Journal and Friend of Knowledge, No. 



V, 1833, p. 165 (for/), bonariensis Raf. = Chilina fluminea Maton). 

 Psendochiliiia Ball, Annals of the Lyceum of Nat. Hist., New York, IX ( 



1870, p. 357 (for Psendochilina limnceformis Ball). 

 Acyrogonia Mabille et Rochebrune, Mission Scientifique du Cap Horn, 



VI, 1889, Mollusques, p. 25. 



The apex in Chilina differs from that of all Lymnaeid snails in the initial 

 half whorl of the embryo, which is tilted up, as shown in fig. 5. Growth 

 of the shell seems to be upward at first, the nucleus lying below the 

 summit. At the end of the third whorl, in C. fulgttrata and several other 



FIG. 5. 



Chilina fulgurata Pils. Young specimen 3.8 mm. long, composed of 3^ whorls. 



species, the color-pattern begins weakly. Previous to this the shell is 

 uniform corneous-brown. The columellar fold is present at a very early 

 stage, but my material does not show when it first appears. 



