332 MAZATLAN UNIVALVES 



The abore series, arranged from their predominating colouis, 

 mutually pass into each other. They present the extremes of 

 form and sculpture, and several possess their opercula. Tablet 

 1569 contains 3 sp. richly coloured and sculptured, with pro- 

 jecting ridges of growth conspicuous near the mouth. 1570, 

 2 sp. after severe fractures, spire twisted. 



Tablet 1571 contains a minute specimen, "038 by '02, which 

 may belong to this species, but develops the spiral keel much 

 earlier and more strongly than usual. 



380. TCTEBITELLA TIGRINA, Kien. 



Icon. Conck. p. 29, no. 22, pi. 4, f. 2. Eve. Conch. Ic. pi. 3, 



sp. 8. Wee. in Zeit.f. Mai. 1850, p. 164, no. 10. 

 Haustator (Turritella) tigrina, H. fy A. Ad. Gen. i. 352. 

 =T. imbricata, Wee. (quasi Lam.) Zeit.f. MaL 1847, p. 178, 



no. 3. 

 Comp. T. Cumingii, JRve. loc. cit. pi. 4, sp. 13. (Panama, 



11 16 fm. Cuming ; Conchagua, Belcher ; Gulf of California, 



sandy mud at low water, Rev. Steel.) 

 Comp. T. imbricata, (Lam. var.) Kien. loc. cit. p. 11, no. 8, 



pi. 9, f. 2a. 

 (Light var.) Comp. T. leucostonia, Veil. Rec. Obs. vol. ii. 



p. 275 '.Kien. loc. cit. pi. 6, f. 2 : Eve. loc. cit. pi. 2, f. 5. 



(Acapulco, Humboldt fy Bonpland ; Gulf JNicoyo, sandy 



mud, 11 fm., Cuming.) 



Very few specimens, and those for the most part dead, were 

 found of this species. It is not swollen in the middle of the 

 spire ; the periphery has a blunt angle ; and the upper whirls 

 have at least five spiral lirulse, The usual painting is a pre- 

 vailing white, with large purple-black patches : but sometimes 

 the coloured part is light reddish brown, very ill defined. 

 Operculum with about 17 whirls, the outer ones fringed with 

 a lighter colour, transversely wrinkled, and with a few spiral 

 rows of hairy tubercles. A specimen with 22 whirls measures 

 long. 3 '33, long. spir. 2 '87, lot. '76, div. 15. 

 Sab. Gulf of California, Reeve. Mazatlan ; extremely rare ; 



L'pool Col. 



Tablet 1572 contains a young sp. of 5 whirls, measuring '049 

 by '018. The first two. are smooth ; the rest much rounded, 

 with fine spiral striae. 



Tablet 1573 contains 2 normal sp., one with operculum, the 

 other after acid. 1574, 1 sp, light var. 



