284 



PROCEEDINGS OF THE NATIONAL MUSEUM. 



VOL. 57. 



nal process is squarish, with an internal medial keel where the septum 

 is prolonged, and above it, in the "bridge", the two rounded holes 

 before referred to. Length of lower valve about 6.5 mm.; transverse 

 diameter 4.25 mm.; vertical diameter about 3.0 mm. Cat. No. 

 227822, U.S.N.M. 



Type locality. — Christmas Island, collected by Mr. Anderson and 

 forwarded to the Museum by Professor Blochmann of Tubingen, 

 Germany. One specimen. 



This is nearest to T. maxilla but is much more regular, the 

 internal arrangements symmetrical, bilaterally identical, and elegant. 



Order TELOTREMATA. 

 Family RHYNCHONELLIDAE. 



Genus HEMITHYRIS Orbigny. 



Eemithiris Orbigny, Pal. Franc. Ter. Cr^t., vol. 4, p. 342, 1847. 

 Hemithyrii Dall, Amer. Journ. Conch., vol. 7, p. 70, 1871; Proc. Acad. Nat. Sci. 

 Phila. for 1875, p. 196. 



Rhynchonella Davidson, Mon. Rec. Brach., pt. 2, p. 163, 1887. 



Type. — Anomia psittacea Gmelin. 



HEMITHYRIS PSFFTACEA Gmelin. 



Anomia psittacea Gmelin, Syst. Nat., vol. 2, p. 3348, 1792. 



Eemithiris psittacea Orbigny, Pal. Franc. Ter. Cr^t., vol. 4, p. 342, 1847. 



Eypothyris psittacea Forbes and Hanley, Brit. Moll., vol. 2, p. 346, pi. 57, figs. 



1-3, 1853.— King, Ann. Nat. Hist., vol. 18, p. 238. 

 Rhynchonella psittacea Reeve, Conch. Icon., Rhynchonella, pi. 1, figs. 2 a-c, 



1861.— Davidson, Mon. Rec. Brach., pt. 2, p. 163, 1887. 



Type locality. — Mari Groenlandiae ; Gmelin. 



Cat. No. 



173692 



173693 



173708 

 173710 

 173712 

 173713 

 173714 

 173726 

 173717 

 181190 

 111013 

 224514 

 111014 

 181263 

 75347 



Locality. 



ATLANTIC HEMISPHERE. 



Figured specimen. Jeffreys Brit. Conch.. 



vol. 5, pi. 99, fig. 4. 

 Figured specimen. Jeffreys Brit. Conch., 



vol. 5, pi. 8, fig. 2. 



Arctic Sea 



Greenland, station 4 



Greenland, station 5 



Greenland, Franklin Pierce Bay 



Greenland, Holsteinborg 



Greenland, Holsteinborg 



Greenland, Holsteinborg 



Greenland, Ungsuak 



Greenland, Upernavik, 13 fathoms 



Greenland, Upernavik 



Greenland 



Greenland, off Hare Id., 90 fathoms 



Greenland 



Collector. 



Belcher 



Valorous Exp 



Valorous Exp 



Valorous Exp 



Valorous Exp 



Valorous Exp 



Copenhagen Mus. 



McLain , 



McLain , 



McLain 



McLain 



McLain , 



Morch 



Number 

 of speci- 

 mens. 



7 

 6 



10 

 1 

 3 



20 

 2 

 1 

 1 

 1 

 2 

 7 

 1 



