120 CONCHOLEPAS. 



3. PisiDiuM. The same, with the posterior side shortest. 

 rig. 112. 



4. Cteeka. Thick ; cardiaal and latera teeth. 'Fig. 113. 

 .5. PoTAMOPHiLA. Two thick cardinal teeth. Fig. 115. 



Marine. 



1. CxPEiNA. Two cardinal teeth, and one remote lateral 

 tooth. Pig. 116. 



2. Venus. Three cardinal; no lateral teeth. Pig. 118, 



119, 119a. 



3. Circe. Short lateral tooth, like Cytherea ; no sinus in 

 the palleal impression. 



4. Cytheeea. Several cardinal teeth ; one very short lateral 

 tooth. Pig. 117, 117«, 1176, 117c, 117^. 



5. Meeoe. Short lateral tooth, like Cytherea ; wedge- 

 shaped, with a deeply hollowed hinge area. 



6. PuLLASTRA. Cardinal teeth notched, shape long, otherwise 

 like Venus. Pig. 120. 



7. AsTAETE. Three cardinal teeth; ligament short. Pig. 



110. 



CONCHIPEEA. Lam. The 11th class of Invertebrata, consist- 

 ing of all those animals which have bivalve shells. Lamarck 

 divides the class into Dimyaria, which have two adductor 

 muscles ; and Mononyaria, which have but one. 



CONCHODERMA. Olfers, 1814. A name under which Mr. 

 Darwin, in his recent work on Cirripides, unites the peduncu- 

 lated cirripides commonly known and described in this book as 

 " CiiSTEEAs" and " Oiioiir." 



CONCHOLEPAS. Lamarck, 1801. (Cokoha, a sheU: lepas, 

 a stone or rock.) Fam. Pupurifera, Lam. Entomostomata, Bl. 

 — JDescr. Oval, imbricated, thick ; Avith a very short spire and 

 large oval patelliform aperture, terminating anteriorly in a 

 slight emargination ; outer lip erenated, with two produced 

 points or teeth towards the anterior ; inner lip smooth, nearly 

 flat, reflected over the last whorl, so as nearly or entirely to 

 cover it ; operculum horny. Marine, only one species known, 

 from Peru.— Obs. This shell is placed near Patella by Lamarck, 



