62 
room vm. bratula (Anomia of Linneus), and Lingula. Of 
Nat. Hist, this genus, which is the last of the Conchifera, 
only one species, L. anatina (Patella unguis. 
Lin.), is known. 
Mollusca. Class 12. Order 1. Pteropoda. 
This compartment also contains one family of 
this order; Hyalasana—which includes the 
genus Hyalsea, and another genus allied to the 
Hyalasa, named by Dr. Leach, Pontica. 
Order 2. Gasteropoda. The families Phyl- 
lidiana, and Semi-Phyllidiana, of the second 
order, are likewise in this compartment. In the 
first are the genera Chitonellus, Chiton, or Coat 
of Mail shell, and the Patella, or limpet. In the 
second, the genus Umbrella. 
Table 17. Calyptracea, Bullseana, Laply- 
siana and Limacina, the four remaining fami¬ 
lies of the Gasteropoda. The genera of the Ca¬ 
lyptracea are, Parmophorus, or Thracian shield 
shell, Emarginula, Fissurella, Pileopsis, Calyp- 
trsea, Crepidula, and Ancylus. The Bullseana 
contain the Bullaea aperta (Bulla aperta. Lin.), 
and several species of the genus Bulla. Laplysia 
and Dolabella are the genera of the next family. 
The shell of the former is a small cartilaginous 
scutcheon, which adheres to the posterior part of 
the back of the animal; that of the latter is 
wholly internal. The genera of the family Li¬ 
macina are, Parmacella, an internal shell, very 
rarely met with; Limax (the Slug), wdiose shell, 
a small testaceous lamina, is contained in a fleshy 
or coriaceous scutcheon, attached to the fore part 
of 
