FAMILY 2. CAPULACEA. 27 
Family 2. CAPULACEA. 
Testa pileiformis animal obumbrans, appendice testacea interna plerum- 
que instructa; cyatho aut lamina solidé interdum sustentata, tamen 
cardine aut ligamento nullo. 
In this family we include nearly the same genera as were associated 
by Latreille under the title of Les Pileiformes, the cup-shaped Calyptra- 
ciens of Lamarck ; they constitute a very natural and well-defined group, 
and are remarkable in being for the most part characterized by the 
development of an internal shelly appendage for the protection of the 
viscera. This appendage passes through a considerable modification of 
form, and its numerous varieties have been selected by authors for the 
purposes of subdivision. There is still, however, another interesting 
feature in the organization of the Capulacea, which is peculiar to this 
family, and may be regarded as a curious instance of natural economy ; 
it is that of depositing a testaceous cup or plate as a support, in situa- 
tions that do not afford good facilities of attachment. This singular 
property, discovered by Defrance as common to the Hipponyces, has been 
lately found by our zealous countryman Mr. Cuming belonging to two of 
the Calyptree. 
The family of the Capulacea may be divided into four genera, as 
follows : 
CREPIDULA. Hipponyx. 
CAaLYPTRAA. PILEOPSIS. 
CREPIDULA, Lamarck. 
Testa ovata vel oblonga, transversim elliptica ; dorso szpissimé con- 
vexo ; subtus cava, vertice, quasi spira, brevissimo, ad marginem 
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