448 CRETACEOUS GASTROPODA 
to be restricted for the large number of fossil species, the recent representant of 
which is Ap. pes-pelicani, Linn. He at the same time very correctly points to the 
distinctions not only of the shells of Aporrhais from Rostellaria, but also of the 
animals; and even should Petiver himself not have pointed out the type of his 
genus, the name would have full authority since 1828, consequently long prior to 
Philippi’s name Chenopus. 
Since my notes, 1. c., pp. 26 and 27, as to the relations of Aporrhais, Rostellaria, 
and others have been written, several new genera of the Azara have been proposed 
by American authors. The more important are the following: 
1. Isopleurus (or Isopleura), Meek (Check list cret. and jur. foss., Smith. 
Misc. Coll., 1864, pp. 20 and 36, with the type Rimella curvilirata, Conrad, 
Journ. Acad. Nat. Sc. II, 1858, p. 331). 
2. Pterocerella, Meek, ibid., p. 36, with the type Harpago tippana, Conr., 
Jour. Acad. N. Sc., III, p. 331. 
3. Leiorhinus, Gabb, Am. Journ. Conch., I, 1865, p. 30, type ZL. californicus, 
Pac. Railroad, V, p. 322. 
4, Platyoptera, Conrad, ibid., p. 31, type P. extenta, Proc. Ac. Nat. Soc., VII, 
p. 260. 
5. Alipes, Conrad, ibid., p. 31, a sub-genus of Aporrhais. 
APORRHAIS SECURIFERA, Forbes, p. 28. 
Rostellaria cancellata, Forbes, Trans. Geol. Soc., Lond., VII, p. 128, or Rost. 
cancellifera, Forbes, ibidem, pl. 18, fig. 18, being based upon a few of the upper 
whorls of A. securifera, Forb., must be added as a synonym of the last species. 
ALARIA Parkinsoni, Hantell, p. 30. 
Agassiz (Sowerby’s Min. Conch., Germ. edit., 1837, p. 881) proposed for this 
species the name Rost. Sowerbyi, though this ought rather to apply to the original 
species of Parkinson, which is from the London clay. 
PTERODONTA, ad’ Orbigny, p. 35. 
Strike out the names Zylostoma, Sharpe, and Varigera, VOrbigny, from the 
synonyms, and refer for farther explanation to page 292, rrzosromin2. 
For Pterodonta bulimoides, Stol., p. 42, read Tylostoma bulimoides. 
For A nobilis, p. 43, read Tylostoma nobile. 
For i Ootatoorensis, Stol., p. 43, read Tylostoma Ootatoorense. 
II. Family,—CYPRAIDZ, p. 44. 
Troschel (Gebiss der Schnecken, vol. I, 18538-1863) replaced this family by four, 
namely, Orprawacea (l. cit., p. 201), Derrzacea (1. cit., p. 214), AupurprrasiaZ, 
p. 216, and Pepvrcvzartacea, p. 189. It cannot be questioned that there are 
