450 MAZATLAN UNIVALVES 
The form appears in the Br. Mus. from Demerara, Capt. 
Friend ; Philippines, Cuming; N. E. Australia, Jukes ; Cape 
York, Macgillivray ; Swan River; Port Natal, Krauss ; Red 
Sea, Major M’ Donald. It is quoted by Dunker from Loander 
and Benguela (legit Dr. G. Tums) ; and by Menke from 
Bathurst, St. Mary, N. 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 alsoa 
variety of the type N. Chemnitzii. 
Hither the species is ubiquitous, and therefore susceptible of 
extreme variation ; or else the characters by which local types 
ean be distinguished from each other, have not yet been 
ascertained. The largest of the Mazatlan specimens only 
measures long. °87, long. spir. 22, lat. °82, div. 100°. 
An elevated sp. ,, °46, - AD ce oe Ayo ae Ors 
A depressed sp. ,, °45, E *O Se «0 hades er LOU 
Hab.—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; Z’pool Col.—(Var. unifasciata.) Guayaquil, Hinds.— 
Se. 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 striule 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. 
; " 
—, sp. ind. 
571. Natica 
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. 
Hab.—Mazatlan ; 1 sp. off Spondylus ; L’pool Col. 
* The numbers will be added in the Appendix. 
