THE NAUTILUS. 101 



be seen. This is a character not shown by P. exarata. The interior 

 as a whole is somewhat iridescent. 



Alt. 21, length 38, breadth 29 mill. Another specimen measures, 

 alt. 18, length 41, breadth 31* mill. 



Specimens were procured by ]\Ir. Frederick Stearns of Detroit, 

 Michigan, on the coast of Japan, Kii Province. 



It is possibly the form referred to by Dunker as P. exarata. From 

 that species it may be distinguished by many characters, such as 

 coloration, that species having black ribs on a whitish ground, and 

 a milky-white interior, whilst Stearnsii has blackish rays, covering 

 several ribs and their interstices, and a chestnut-brown area inside 

 the muscle-attachment. The peculiar sculpture of the inside is also 

 of itself diagnostic. Dunker (Index Moll. Maris Japonici, p. 157) 

 also mentions Patella mazatlanica Gray in connection with his " e.r- 

 arata.'" This shell is really a native of Chili, not Mazatlan ! Dr. 

 Ruschenberger collected specimens at Concepcion, which correspond 

 exactly with Gray's figures (Beechey's Voy., Zool., pi. 39, fig. 12.) 

 It is a more straightly conical form than P. exarata, differently col- 

 ored outside, and having a small chestnut-brown area inside the 

 muscle-impression ; this area being much smaller than in P. Stearnsii, 

 which also difl^ers from it in the sculpture of the interior described 

 above. Gray called his species " mazatlandiea. " 



Figures of P. Stearnsii will be given in ]\Ir. Stearns' catalogue of 

 the shells collected by him during his travels in Japan, now in press. 



MOLLTJSCA OF THE UNITED STATES. 



BY .JOHN H. CAMPBELL, PHILADELPHIA. 



The project of establishing a great National Collection of United 

 States Mollusca, through the co-operation of members of the Amer- 

 ican Association of Conchologists, has been received with such favor, 

 that it is but a question of time when the collection will be one of 

 the finest special exhibits in the world. The Philadelphia Academy 

 of Natural Sciences, (through its Conchological Conservator) has 

 offered facilities for the permanent exhibition and preservation of 

 the collection, and already a goodly number of fine shells has been 

 received and mounted. 



With the preparation and mounting of the specimens, comes the 

 question of correctly naming them ; and herein is presented the most 



