POTAMIDES. 161 



Subgenus Telescopium, Montf., 1810. 

 P. TELESCOPIUM, Linii. PI. 33, fig. 56. 



AVhorls with about three spiral sulci, dividing broader, flat-topped 

 ridges, base strongly ridged, varying to nearly smooth, channeled 

 around the spirally twisted columella ; chocolate brown of varying 

 shades, sometimes obscurely banded. Length, 3-4 in. 



India, Singapore, Borneo, Philipjyines, etc. 

 P.fuscum, Schum., and P. indicator, Montf., are other names for 

 this species. 



Subgenus Cerithidea, Swainson, 1840. 

 C. Montagnei, d'Orbigny. PI. 33, figs. 57, 58 ; PI. 32, fig. 50. 



Chestnut or chocolate color, Avith a narrow, medium white band, 

 often with darker bands, interior banded with chocolate and light 

 yellowish brown, base of body whorl defined by a slight ridge. 

 Length, 1"5-1"75 in. 



Panama to Lotver California ; Cerros Is. 

 It is C. Eeeviamim, C. B. Ad., and C. Largillierti, Phil. 



Var. PULCHRA, C. B. Ad. Fig. 50. 



"Whorls varicose, the sculpture stronger, often becoming subnodose. 

 Gtdf of California to Panama ; f Chili. 



The synonymy includes C varicosa, Sowb. (preocc. = C. fortius- 

 culum, Bayle, fig. 58), C. Hegivischii, Phil, and C. valida, C. B Ad. 

 C. OBTUSA, Lam. PI. 33, figs. 59-61, 63 ; PI. 32, fig. 53. 



Ventricose, sinuously longitudinally ribbed, spirally grooved, 

 rendering the ribs nodulous ; chestnut color, light banded below the 

 suture, and again below the periphery of the body whorl ; apex 

 decollated. Length, 2 in. 



Malacca, Singajiore, Philippines. 



Var. Kieneri, Hombr. et Jacq. Figs. 61, 53. 

 Narrower, ribs more distant, apex not decollated. 



Var. QUADRATA, Sowb, Fig. 63. 



Whorls white-banded in the middle instead of at the suture. 



C. DECOLLATA, Linn. PI. 32, fig. 54. 



Chestnut or chocolate color, usually more or less banded in dif- 

 ferent shades, with frequently a white band at the suture, closely 

 longitudinally ribbed and spirally striate, the strise appearing mostly 

 in the intei-stices of the ribs, apex decollated. Length, 1*33 in. 



India, Timor, Madagascar, etc. 

 Turbo pidcher, Dillw., is a synonym. 

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