78 



BULLETIN 100, UNITED STATES NATIONAL MUSEUM. 



Genus HAPLOSTICHE Reuss, 1861. 



HAPLOSTICHE DUBIA (d'Orbigny). 



Plate 13, figs. 8, 9. 



" Orthoceratia Zoophytica minuscula" Soldani, Testaceographica, vol. 1, pt. 2, 



1791, p. 93, pi. 98, fig. A. 

 Nodosaria dubia d'Orbigny, Ann. Sci. Nat., vol. 7, 1826, p. 252, No. 10. 

 Lituola dubia Parker, Jones, and H. B. Brady, Ann. Mag. Nat. Hist., ser. 4, 



vol. 8, 1871, p. 263, pi. 9, fig. 30. 

 Lituola soldanii Jones and Parker, Quart. Journ. Geol, Soc, vol. 16, 1860, 



p. 307, no. 184. 

 Haplostiche soldanii H. B. Brady, Rep. Voy. Challenger, Zoology, vol. 9, 1884, 



p. 318, pi. 32, figs. 12-18. 

 Haplostiche dubia Cushman, Bull. 71, U. S. Nat. Mus., pt. 1, 1910, p. 96, figs. 



140, 141 (in text). 



This species is rather common in many parts of the region. Both 

 microspheric and megalospheric forms of the species occurred usual- 

 ly at the same station. Tlie microspheric form attains a much larger 

 size, as is usual. The aperture in the larger specimens becomes 

 decidedly complex, the teeth assuming a dendritic form. The smaller 

 megalospheric specimens usually have a much simpler form of aper- 

 tural teeth. In the development of a specimen there is a change 

 from a simple tooth in the earlier chambers through gradual changes 

 to the complex aperture of the adult. 



In depth the stations range from 37 to 540 fathoms (67 to 987 

 meters), and bottom temperatures from 40.1° to 59.0° F. (3.5° to 

 15° C), but most of the temperatures are above 50° F. (10° C). 



Haplostiche dubia — Material examined. 



