i6 WORMS. TESTACEA. 50. Nautilus. 



broad longitudinal ribs covering the whole surface, 

 and a few concave spines towards the larger end. 



totttitgue BriL Shells. p. 183. tub. 5.7.3. 



Shell about 4 inches long and 2 wide, dark-er art the fmaller end, 

 straight, a little rounded and oblique at the larger end, with 10 or 

 aa very broad ribs running the whole length, andafe-w mternieUiate 

 Smaller ones at the narrow end. 



C. Univalves^ mid more r less spiral. 

 50. NAUTILUS. 



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

 whorls 4 or 5, twisted with deep joints. 



Adams Microfc. 1. 14, /. 29. Watt. min. Sketls.f> 63. 



*. With the spires reversed. Walk. /. 64. 



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

 the inhabitant is alive, convex above, fiat beneath, with 10 grooved 

 joints in the first spire. 



325. N. crjspus. Spiral, with the aperture semi cordate : 

 outer whorl with about 20 flexuous crenate joints. 



Adams Micr. 1. 14.7. 30. Wolk. mi*. Shells, f. 65. 



4Af// minute, opake, white, granulate and marked with flexuoui 

 strias, the outer edge carinate ; umbilicabe each side, wilh a central 

 siphon. 



36. N. lavigatulus. Spiral, semipellucid, white, glossy, 

 with smooth joints. 



AdamtMicrt.t. 14-/.32. Walk.f.fy. Miaute. 

 3S7. N. rotatus. Spiral, smooth, with a semicordate 

 apperture, and 6 joints marked with raised flexuous 

 striae ; the keel very entire. 

 Montague Brit. SkeUs. t. 1 5. /. 4. N . C al car. 



328. N. dcpressulus . Spiral, opake, white, subumbili- 

 cate both sides, with numerous depressed joints. 



Adams Micr. t. 14. /. 33. WalA.f.CS. Minute. 



^29. N. umbilicatula^ Spiral, opake, white, umbili- 

 cate, with grooved joints. 



ddams Micr. t. \\._f. 34. Walk.f. 69. .Minute. 



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

 sides, with fine joints. 



Adams Micr. t. 14. /. 35. ll'alk.f.TQ. Minute, 



33 [. N. lacustris. Spiral, smooth, pellucid, horn-colou 

 with 4 whorls bordered on the outer edge with an 

 opake whitish spiral line. 



P.hilot. Trans. 76 t. i. Montague t. 6. f. 3. 



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

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

 deeply umbilicate beneath : aperture semidvate. 



332. N. lobalulus. Spiral, lobed, flattish, confluent, 

 warty, with semilunar very thin partitions. 



Adams Microfc. p, 642. tab. 14. f. 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 narrow. 



333. N. carinatnlus. Whitish, transparent, carinate, 

 with a narrow oval aperture. 



Adams Microfc. t. i.f. 37. Walker /. 72. Minute. 



