CONCHOLOGY. 



Length, nearly half an inch : breadth, 

 nearly seven-tenths of an inch. 



Plate 3. fig. 6. 



This species is perhaps rare ; it does 

 not exactly agree in all its characters 

 with the genus, but approaches nearer 

 it than to any other with which we are 

 at present acquainted ; it resembles Unio 

 Undnlata, for the young of which it 

 Blight readily be mistaken. 







GENTS CTCIAS. 



Shell almost orbicular, or a little trans- 

 verse, without fold on the anterior mar- 

 gin; two or three primary teeth, and 

 lateral, remote, lamelliform ones on each 

 side. 



Observ. The shells of which this ge- 

 nus is composed were formerly placed 

 with the Cardia and Teltince ; to the for- 

 mer they are more closely allied ; it was 

 originally established by Scopoli under 

 the name of Sph&rium, this was changed 

 by Lamarck to Cyclas, which is now 

 adopted by Latreille and other writers, 

 notwithstanding the previous application 

 of the term to a genus of plants. 



1. C. Nimilis. Shell suborbicular con- 

 vex, base a little flattened ; with nearly 

 .equi-distant, raised, concentric lines, 

 giving a sulcated appearance to the sur- 

 face, and generally a more conspicuous 

 elevated darker wave, marking the for- 

 mer year's growth of the shell. Epider- 

 mis brown or ferruginous; beak nearer 

 central, and obtuse ; hinge with minute 

 very oblique teeth, lateral ones very dis- 

 tinct, elongated, and considerably resem- 

 bling those of the next species. 



. Length seven-twentieths of an inch : 

 breadth two-fifths. 



Plate 1. fig. 9. 



Very much resembles Tellina Cornea 

 of Authors ; is found in plenty in the 

 river Delaware ; animal viviparous ; from 

 one specimen three pale yellow active 

 young ones were taken, the largest of 

 which measured in breadth three twen- 

 tieths of an inch, in the month of May. 



2. C. Dubia. Shell oblique, subovate, 

 convex, concentrically wrinkled, very 

 pale horn colour or whitish, with some 

 times a darker, but not raised band, 

 marking the preceding year's growth of 

 the shell ; beaks placed much nearer one 

 end; within whitish, primary teeth very 

 distinct, in one valve two divaricating 



ones, in the other but one, exterior late- 

 ral lamina! tooth very small. 



Length five-twentieths of an inch, 

 breadth three-tenths. 



Plate l.fig. 10. 



Inhabits the river Delaware in compa- 

 ny with C. SimiKs, and very much resem- 

 bles Tellina Amnica of Authors. 



The shells here described are in the 

 collection of the Academy of Natural 

 Sciences of Philadelphia. 



It was originally the intention of the 

 writer of this article to insert here, not 

 only descriptions of the fresh water and 

 land shells, but those of the coast also ; 

 finding, however, that the descriptions 

 of the latter were by far too voluminous 

 to be comprised within the space allot- 

 ted to this article, and that they had 

 more generally found a place in the sys- 

 tems, the design is, with respect to this 

 work, necessarily relinquished. To all the 

 species here described, with the excep- 

 tion of two, we have been constrained to 

 adapt specific names ; but should it ap- 

 pear that we have been anticipated by 

 the labours of some recent Concholoerist, 

 whose writings we have no opportunity 

 to consult, we shall readily bow to the 

 right of priority, which ought unques- 

 tionably to be on all occasions imperative 

 and exclusive. 



The primary divisions of the Linnsean 

 system, in the latest edition of the " Sys- 

 tema Naturae," as before observed, con- 

 sist of three orders, Multivalve, Bi- 

 valve, and Univalve, each of which is sub- 

 divided into genera. The Multivahes 

 contain the chiton, lepas and pholas ; the 

 Bivalves, mya, solen, tellina, cardium, 

 mactra, donax, venus, spondylus, chama, 

 area, ostrea, anomia, mytilus, and pinna ; 

 and the Univalves, argonauta, nautilus, 

 conus, cypraea, bulla, voluta, buccinum, 

 strombus, murex, trochus, helix, nerita, 

 haliotis, patella, dentalium, serpula, 

 teredo, and sabella. Which see. See 

 also SHELLS. 



CONCLAVE, the place in which the 

 cardinals of the Romish church meet, 

 and are shut up, in order to the elec- 

 tion of a pope. The conclave is a range 

 of small cells, ten feet square, made of 

 wainscot : these are numbered,and drawn 

 for by lot. They stand in a line along 

 the galleries and hall of the Vatican, with 

 a small space between each. Every cell 

 has the arms of the cardinal over it. 

 The conclave is not fixed to any one 

 determinate place, for the constitutions of 

 the church allow the cardinals to make 



