274 WORMS. TESTACEA. 66. Oftrea. 



Anatind* Shell pellucid, lamellate and laterally incurved. 

 Spengler cat al. raif. tab. 6. fig. 1,2. 

 Cbemn. ctncb. 8. tab. 70, f 658. tab. yi,fi. 659. 

 lnhab$&Nicobar IJlands : about an inch broad, and including 

 the curvature 3 inches long: its fhape in fome manner refem- 

 bles a. duck when fitting : Jhellih'in, brittle, varied with white 

 and vioJet, 



, 



Dilwviana* Shell plaited on the outfide; the margin with erect acutan- 

 gular teeth. 

 Found in a foffile Hate in the calcareous mountains of Sweden, 

 about the fize of a common oyfterj the margin with ereft 

 ferratures formed as it were of the imbricate lamellae of the 

 fhell, and tranfverfely ftriate : valves with pectinate plaits 

 and acute wrinkles. 



Folium. Shell ovate, obtufely plaited at ihe fides, parafitical. 



Barbut, tab. 9, fig . 2. Rumpfi, Muf. tab. 47, A. 



Petiv. Ami. tab. 10, f. I, Argent, conch, t* 19. F. 



Klein Ojir. tab. 8. jig. 22. SpengL conch, tab. I. H. 



Knorr Vergn. 1. tab. 23, fig. 2. 



Chemn. conch. 8. tab. 71* fig. 662 — 666 t 

 Zi Schrcct. litterat. 2. tab, I. fig, 5, 6. 



Inhabits the Indian Ocean, where it is frequently found adhering 

 to Gorgoninc : fhell (Iraw-coulour, pale tawny or violet, within 

 filvery : hinge with a triangular hollow : upper-<vahe turgid on 

 the back towards the middle, wrinkled each fide and tranf- 

 verfely ribbed ; loiver.<vahe lefs flatter and grooved in the 

 middle. 



Orbicularis Shell orbicular, flat, with an entire crenate margin, 

 Gualt. tefl, tab, 104, G. Chemn* 8. taty. 74. fig. 680 ? 

 Inhabits — Shell with a very obrufe margin, about the iize 

 of the end joint of the thumb. 



*Edulis» Shell nearly orbicular and rugged, with undulate imbricate 

 fcales : one valve flat and very entire. 

 Pennant Brit, Zool. iv. tab, 62, lower figure. 

 Lister An, Ang. tab. 4. fig, 26. 

 Lister conch, tab. 202. fig. 36. /. 203, j. 37. 

 Bon an. recr. 2. fig. 70. Muf Kirch. 2. f. 68. 

 Gualt. tejl. tab. 102. A, B. Argenv. Zoom* t* 5. A, 

 Bafter op.fuhfi 2. tab. 8, fig. 1,2. 8, 9, 

 Ginann. adr. 2. tab. 18. fig. 127. 

 Knorr Vergn. 3. tab. 2^fig. 2, t. 25.fi. 2. 

 Chemn. conch. 6. tab. 74. fig. 682. 

 2. Adanfi. Seneg. 1. tab. 14. fig* 3. 



Lister* tab. 193, 194. Kkinoftr* tab. $,f. 2\.\ 



Bern. 



