192 TURBO. TURBAN. 



rita tribes, as the imagination of different authors has fan- 

 cied their approximation. They are all of modern disco- 

 very, and in none of them is the pillar-lip sufficiently trans- 

 verse to entitle them to a place among the. Nerites : we 

 think therefore that they form a singularly appropriate di- 

 vision, in contrast with the second, where the pillar-lip is 

 placed rather transversely and flattened, but without the 

 groove and perforation. 



A. The pillar-lip flattened, with a groove along its mid- 



dle which terminates in a perforation, 1 to 6. 



B. The pillar-tip flattened, without groove or perfora- 



tion, 7 to 15. 



C. Solid, and imperf orate behind the pillar, 16 to 31. 



D. Solid, and perforated behind the pillar, 32 to 34. 



E. The spires cross-barred, or reticulate, 35 to 56. 



F. Tapering, but not cross-barred, 57 to 66. 



G. The aperture toothed within: spires regular, 67 



to '78. 



H. The spires reversed, /9 to 85. 

 I. Flat, and resembling the Helix, 86 to 92. 

 K. Indistinct species, 93 to 105. 



A. The pillar-lip flattened, with a groove along its middle y 

 which terminates in a perforation, 1 to 6. 



1. Turbo pallidulus. Pallid Turban. Fig. 85, 86. 



Nerita pallidula. Da Costa, pi. 4. f. 4, 5 Donovan, 

 pi, 16. f. I Dorset Cat. pi. 20. f. 4, 5. 



Shell transversely oval, thin, semitransparent, very ob- 

 scurely striate longitudinally, and slightly wrinkled across, 

 whitish covered with a pale brown or greenish skin : spires 

 three or four, the first very large and much spread towards 

 the outer margin, the others placed laterally and flat upon 

 the surface, or having the appearance of being rather sunk 

 beneath it : aperture ample, nearly orbicular, slightly an- 

 gular towards the pillar, much spread at the margin ; the 

 outer-lip thin, somewhat reflected and fringed by the outer 

 skin; pillar-lip broad, oblique but not transverse, with a 

 rather narrow groove which terminates in a somewhat 



spiral 



