130 THE NAUTILUS. 



of the tropics. The shell is the Placuna placenta of science, and is 

 well known in China, the common name being ihe Chinese window 

 oyster. It is employed there also for windows and used in lanterns. 

 The Chinese grind up the shell and make from it the silver paint so 

 common in their water colors. The bivalve is very common in 

 the Philippines, and forms a very good and cheap substitute for 

 glass. — The Phila. Record. 



I'niosiiu; in a Tunnel I am interested in two examples of 



Margaritana margaritifera var. falcata, taken in a water tunnel near 

 Santa Cruz, in this state (California), 700 feet from the mouth of the 

 tunnel, and 300 feet underground. They differ from the normal 

 specimens in being both unusually large and thin, the nacre being 

 very richly colored. — Fred L. Button. 



Purpura coronata Lam. in America. — This well-known West 

 African species has been reported from Demerara and Trinidad by 

 the Rev. A. H. Cooke. Living specimens were collected at Liv- 

 ingston, Guatemala, in the spring of 1899, by Mr. Silas L. Schiuno, 

 and are now in the collection of the Academy. — H. A. Pilsbry. 



Additional Chitons from the Pliocene of the Caloosa- 

 hatchie River, Florida. — In recently working over (with the 

 assistance of Mr. F. G. Vanatta) a lot of fine material, mostly ob- 

 tained in cleaning the larger mollusca, collected by the late Dr. H. E. 

 Griffith, ten valves of Chitons were found. These were kindly stud- 

 ied by Dr. Pilsbry, with the following results : 



Ghcetopleura apiculata Say. One head and two central valves. 



Tschnochiton papillosus C. B. Ads. Two central valves. 



Jschnochiton striolatus Gray. One head and one central valve. 



Acanthochites fygmceus Pilsbry. One central valve. 



The two other central valves were too imperfect for determination. 



Isch. striolatus has only been recorded recent from St. Thomas and 

 Barbados. 



Dr. Dall. in his work on the " Tertiary Fauna of Florida" (Trans. 

 Wagner Free Inst. Sci., Vol. Ill, pt. 2, p. 435), records but one 

 species, Acanthochites spiculosus Reeve; "A fragment of a central 

 valve," '' too imperfect t<> make the identification certain." — C. W. 

 Johnson. 



