450 MAZATLAfr UNIVALVES 



The form appears in the Br. Mus. from Demerara, Capt. 

 Friend; Philippines, Cuming ; IS". E. Australia, Jukes; Cape 

 York, Macgillivray ; Swan River ; Port Natal, Krauss ; Hed 

 Sea, Major M' Donald. It is quoted by Dunker from Loander 

 and Benguela (legit Dr. Gr. Tarns) ; and by Menke from 

 Bathurst, St. Mary, 1ST. W. Africa (legit Melchers.) In Mus. 

 Cuming may be seen many varieties from white to dark, with 

 or without zigzag markings and with the spire more or less 

 elevated, all from the Society Is. As far as can be judged 

 from the diagnosis, the Natica iostoma of Menke is also a 

 variety of the type IN". Chemnitzii. 



Either the species is ubiquitous, and therefore susceptible of 

 extreme variation ; or else the characters by which local types 

 can be distinguished from each other, have not yet been 

 ascertained. The largest of the Mazatlan specimens only 

 measures long. '87, long. spir. V 22, lat. '82, div. 100. 



An elevated sp. '46, '12, ,, '42, 90. 



A depressed sp. *45, '08, "44, 110. 



Hob. For various localities, v. supra. (N. Chemnitzii, Pfr.) 



Panama ; 60 sp. on soft mud near low water mark ; C. B. 



Adams. Guaymas, Lieut. Green. Mazatlan ; rare and 



small ; L'pool Col. (Var. unifasciata.) Guayaquil, Hinds. 



S. W. Mexico, P. P. C. 



Tablet 2042 contains a young shell, ' 08 long, displaying the 

 normal shape and colour, with the spire dark purplish brown. 

 Also an operculum, ' 12 long, with the callus on the spire not 

 yet worn away ; inner margin corrugately serrated, to corres- 

 pond with the spiral striulae which are more distinct than in 

 the adult. 



Tablet 2043 contains * sp. very young. 2044, 4 sp. various 

 ages. 2045, 1 sp. with its operculum, and 2 separate opercula. 

 2046, 4 sp. richly coloured, olive. 2047, 3 do. pattern clouded 

 at the end. 2048, 4 do. light shade. 2049, 3 do. slate colour. 

 2050, 2 sp. shewing diversity of form. 



571. NATICA , sp. ind. 



Tablet 2051 contains a minute shell, * long, resembling 

 "N. maroccana, but of a light buff colour, nucleus smaller, 

 upper whirls flattened, and sutural region not grooved. 

 Hob. Mazatlan ; 1 sp. off Spondylus ; L'pool Col. 



* The numbers will be added in the Appendix. 



