43 4 CRETACEOUS GASTROPODA 
shell of Gastropteron comes very close to that of Lobiger, and as Krohn remarks 
also much resembles that of Aglaia (Doridium). The same author, however, 
remarks that the radula of the young Gastropteron appears to be instructed with 
four longitudinal rows of hook-like teeth, which would evidently speak for a 
greater relation of Gastropteron to Philine than to the Oxyvorrps, in which it had 
been placed. A. Adams (Ann. mag. nat. hist., 1861, VIII, p. 189), in describing a 
new species, G. sinense, says that three specimens which he observed “ appeared 
to want the power of crawling altogether; the animals, after taking short flights, 
usually upside down, etc.” The same author is also of opinion that the genus 
may better be placed in the Oxyyorrpz, to which it must be referred if the 
dentition agrees, for it must be observed that Krohn is by no means perfectly 
certain that his animal was truly the larva of Gast. Meckelit. 
2. Aglaia, Renier, 1804 (Doridiwm, Meckel, H. and A. Adams, Gen. IT, 
p. 27). 
3. ? Posterobranchea, dOrbigny, 1835 (ibid. p. 28) can only doubtfully 
remain in this family, as the position of the branchial plume on the left side and 
the emarginated or lobed hinder part of the foot appears to indicate further and. 
more important distinctions in a classificatory sense. 
4. Philinopsis, Pease, 1860 (Proc. Zool. Soc., Lond., p. 21). Shell rudimentary. 
5. Volvatella, Pease, 1860 (bid. p. 20) has a pyriform shell, aperture broad 
in front, posteriorly contracted and produced, forming a circular hole. 
6. Cryptophthalmus, Ehrenberg, 1831 (H. and A. Adams’ Gen. IT, p. 23). 
7, Phanerophthalmus, Adams, 1850 (ibid. page 25) (Xanthonella, Gray, 1850). 
8. Chelidonura, Adams, 1850 (ibid. p. 26; Hirundella and Hirundinella, 
Gray, 1850). 
9. Bullea, Lamarck, 1801. This name ete to be reserved for the species 
which have a comparatively solid, in all probability external shell, in which the 
spire is reduced to a small inverted point, the outer lip being largely expanded and 
posteriorly produced like in Chelidonwra, the inner rather thickened. Deshayes 
described lately (Paris fossils, 2nd edit., pp. 650-651, pl. 36) three fossil species. 
Megistoma, Gabb, 1864 (Paleeont. Calif. I, p. 144), which was proposed for the 
eretaceous Veg. striata, must be considered as identical with Bullea, and as there 
is already a species of Deshayes called B. striata, the cretaceous species may be 
ealled B. Gabbiana, after the distinguished paleontologist of the Geological Survey 
of California. 
10. Philine, Ascanias, 1772 (H. and A. Adams, Gen. II, p. 24) has a short, 
laterally convolute spire, the margins of the aperture largely expanded; the shells 
are very thin, membranaceous, being internal. The recent species are rather 
numerous and the animals particularly large. 
11. Smaragdinella, Adams, 1850 (ibid. p. 22) is distinguished from Philine by 
a more distinctly marked involute spire, the shell being much narrower posteriorly, 
partially external; the inner lip has posteriorly a projecting thin, particularly 
twisted plate. In addition to the few species described under this generic name, 
