160 WORMS. TESTACEA. 5a. Nautilus. 



broad longitudinal ribs covering the whole surface, 

 and a few concave spines towards the larger end. 



Montague Brit'. Shells. p. 183. tab. 5./. 3. 



Shell about 4 inches long and 2 wide, darker at the ("mailer end, 

 straight, a little rounded anJ oblique at the larger end, with to or 

 i2 very, broad ribs running the whole length, and a few intermediate 

 Trnaller ones at the narrow end. 



C Univalves, and more or less spiral, 

 50. NAUTILUS. 



324. N. Beccarii. Spiral with- the aperture obovate : 

 whorls 4 or 5, twisted*with deep joints. 



Adams Micrqfc. t. 14. /. 29. Walk % min. Shells./. 63. 



2. With -the spires reversed. Walk. /. 64. 



Shell minute, white covered with a brown skin, crimson when 

 the inhabitant is alive, convexttbove, .flat beneath, with 10 grooved 

 joints in the first spire. 



325. N. crispm. Spiral, with the aperture semicordate : 

 outer whorl with about 20 flexuotis crenate joints. 



Adams Micr. t. \a.J. 30. Walk, min. Shells, /. 65. 



Shell minute, opake, white, granulate and marked with flexuou* 

 striae, the outer edge carinate ; umbilicate each side, with a central 

 siphon. 



326. N . Icevigatulus* Spiral, scmipellucid, white, glossy, 

 with smooth joints. 



Adams Micro, t. 14./. 32. Walk.f. 67. Minute. 



321. N.rotatus. Spiral, smooth, with a semicordate 

 apperture, and 6 joints marked with raised flexuous 

 striae ; the keel very entire. 



Montague Brit. Shells, t. 15. /. 4. N. Calcar. 



3^8. N . depressulus . Spiral, opake, white/ subumbili- 

 cate both sides, with numerous depressed joints. 



Adams Micr. t. 14../. 33. Walk. /. 68. Minute. 



3.29. N. umbilicatulm\ Spiral, opake, .white, umbili- 

 cate, with grooved joints. 



Adams Micr.t. 14./. 34. Walk./..6g.. Minute. 



330. N.crassulus. Spiral, thick, white, umbilicate both 

 sides, with fine joints. 



, Adqms ■ Misr. t.14./. 35, Walk.,/. 70. Minute.. 



331' N.lacusiris. Spiral, smooth, pellucid, horn-colour, 

 with 4 whorls bordered on the outer edge with an 

 opake whitish spiral line. 



Phi ; los. Trans. 76 t. 1. Montague t. 6./. 3. 



Shell about 2 lines broad, comprefsed, slightly carinate, some- 

 times rufous brown, with 3 joints in the outer whorl, flat and 

 deeply umbilicate beneath : aperture semiovate. 



3j2. N± lodatulus. Spiral,, lobed,. flattish, confluent, 

 warty* whh semilunar very thin partitions. 



Adams Micro/c. p. 642. tab. 14./. 36. 



Shell minute, white or yellowish, more or less orbicular or ob- 

 long, convex above, flat underneath, with 6-8 parallel lobes ; aper- 

 ture very harrow. 



3^2- N. car ina tulus. "Whitish, transparent, carinate, 

 with a narrow oval aperture. 



Adams Micro/c. 1. 1 4./. 37. Walker/. 72. Minute. 



