58 BULLETIN *71, UNITED STATES NATIONAL MUSEUM. 



Distribution. — This small but attractive species is usually associ- 

 ated with coral-reef conditions in the shallow or comparatively shallow 

 waters of tropical islands. Brady records it from the Pacific under 

 such conditions. The material I have had is from Nero stations 

 2034 in 175 fathoms, 2042 in 55 fathoms, and 2070 in 285 fathoms, 

 off Honolulu, Hawaiian Islands. 



This species very evidently belongs to the genus Massilina instead 

 of to Spiroloculina, as its early development seems to be invariably 

 quinqueloculine, and it is only the last few chambers that are 

 spiroloculine. 



Genus ARTICULINA d'Orbigny, 1826. 



Nautilus Batsch (part), Conch, des Seesandes, 1791, p. 3. 



Articulina d'Orbigny (type, A. conico-articulata (Batsch)), Ann. Sci. Nat., 



vol. 7, 1826, p. 300.— H. B. Brady, Rep. Voy. Challenger, Zoology, vol. 9, 



1884, p. 182. 

 Vertebralina Parker, Jones, and H. B. Brady (part), Ann. Mag. Nat. Hist., 



ser. 3, vol. 16, 1865, p. 22. 



Description. — Early chambers usually quinqueloculine or trilocu- 

 line, later ones in a uniserial arrangement, varying considerably in 

 number according to the species; aperture in the adult a rounded, 

 usually elliptical opening, in a depression with a definite phialine lip. 



This genus is clearly a modification from Triloculina or Quinqueloc- 

 ulina, in which the early development shows clearly its relations to 

 those genera, and the later development is an additional character 

 similar and analogous to the uniserial development in Bigenerina, 

 Clavulina, Vaginulina, etc. Such genera represent a final develop- 

 ment along a specialized line, and the same is true here. 



In some of the species the uniserial characters become relatively 

 nearly the whole of the test, the triloculine or quinqueloculine portion 

 being but a bulbous basal portion; in other species there is a rather 

 even balance between the two portions. Those showing the greatest 

 relative development of the uniserial portions may be definitely 

 placed as the highest development of the genus. 



ARTICULINA CONICO-ARTICULATA (Batsch). 



Plate 22, fig. 6. 



Nautilus (Orthoceras) conico-articulatus Batsch, Conch, des Seesandes, 1791, 



p. 3, pi. 3, fig. 11. 

 Vertebralina conico-articulata Parker, Jones, and H. B. Brady, Ann. Mag. 



Nat. Hist., ser. 3, vol. 16, 1865, p. 22, pi. 1, fig. 2.— Goes (part), Abhandl. 



Kongl. Svensk. Vet. Akad. Handlingar, vol. 19, 1882, p. 121, pi. 9, figs. 317, 



3176; Bull. Mus. Comp. Zool., vol. 29, 1896, p. 88. 

 Articulina conico-articulata H. B. Brady, Rep. Voy. Challenger, Zoology, vol. 9, 



1884, p. 185, pi. 12, figs. 17, 18; pi. 13, figs. 1, 2.— H. B. Brady, Parker, 



and Jones, Trans. Zool. Soc, vol. 12, 1888, p. 216, pi. 40, figs. 7-9.— Egger, 



Abhandl. kong. bay. Akad. Wiss. Miinchen, CI. n, vol. 18, 1893, p. 224, pi. 



