260 BULLETIN 93, UNITED STATES NATIONAL MUSEUM. 



regarded as an iinprogressive form, which retains cliaracters of the 

 ancestral stock of the genus, elsewhere found only in an early stage of 

 development. 



The Italian Oligocene species, Tetraelita isseli De Alessandri,^ be- 

 longs to this group and is closely related to 2\ roseck 



TETRACLITA ROSEA (Krauss;. 



Plate 5S, fig. 4. 



1848. Conia rosea Krauss, Die Siidafrikanischen INIollusken, p. 136, pi. 6, 



fig. 28. 

 1854. Teiraclita rosea Krauss, Dauwin, IMonograpli, p. 335, pi. 10, figs. 



o'/-3(?. 



Dlstrihidlon. — South Africa ; Australia. 



A single large specimen of this species in the National Museum is 

 labeled " Orange Harbor," no doubt erroneously. No collector given. 

 This specimen is figured {\A. 58, fig. 4) to show the features of the 

 pores. It is 25 mm. in diameter. There is a series in the collection of 

 the Academy of Natural Sciences of Philadelphia from Eichmond, 

 near Melbourne, Victoria, collected by Mrs. Agnes F. Kenyon. 



Genus ELMINIUS Leach. 



1825. Ehiiinius Lkach, Zoological Journal, vol. 2, p. 210. 

 1854. Elminins Leach, Daewin, Monograph, p. 345. 



Barnacle conic or cylindric; compartments four; parietes not 

 porous ; basis membranous. 



Tyj)e. — E. Mngii Gray. 



Distribution. — Austral in both hemispheres; littoral. • 



Elininius differs from Tetraelita by the absence of pores in the 

 parietal walls. It holds such a relation to Tetraelita as GMrona to 

 the typical Balani. Tetraelita. is a more evolved genus. Leach did 

 not mention a species in his table defining this genus. In fact no 

 species liad then been described. I am selecting E. kingii, the 

 first species described, as the genotype. 



ELMINIUS KINGII Gray. 



1831. Elininius kingil Gray, Zoological INIiscellaiiy, p. 13. 

 1831. Elminius leaehii King and Broderip, Zoological Journal, a'oI. 5, p. 334. 

 1854. Elininius kingii Graj', Dakwin, Monograph, p. 348, pi. 11, figs. 6«-6e. 

 1911. Elminius kingii Gray, Obtmann, Princeton Patagonian expedition, 



p. 637. 

 1914. Elminius kingii Gray, Stebbing, Proc. Zool. Soc, London, p. 376. 



Distribution. — Falkland Islands, Tierra del Fuego, Chiloe (Dar- 

 win). Darwin describes it as follows: 



Shell smooth, gray, or dirty white; radii broad, smooth edged. Scutum witli- 

 out an adductor ridge. Tergum with the spur distinct from the basiscutal 

 angle. Scutum and tergum sometimes calcified together. 



1 PaUpontographia Italica, vol. 12, 1906, p. 318. 



