DESCRIPTION OF GENERA AND SPECIES. 



FORAMINIFERA. 



Genus GLOBIGERINA d'Orbigny. 



Globigerina ? mantoensis Walcott. 

 Plate i, Figure i. 



Globigerina ? mantoensis WALCOTT, 1905, Proc. U. S. Nat. Mus.,vol. xxix, p. 10. (Described as below 

 as a new species.) 



A single specimen of what is probably a species of Foraminifera occurs in a 

 compact, gray limestone. It is elongate-oval in shape, convex, and divided longi- 

 tudinally by a narrow furrow into two lobes, which are marked by more or less 

 irregularly arranged and not very deep depressions at right angles to the central 

 furrow. 



Formation and Locality. Middle Cambrian: (C5) Lower limestone member 

 of the Kiu-lung group [Blackwelder, 19070, pp. 37 and 39 (first list of fossils), and 

 fig. So (bed 30), p. 29], 3.2 miles (5.1 km.), southwest of Yen-chuang, Sin-t'ai dis- 

 trict, Shan-tung, China. 



Collected by Eliot Blackwelder. 



PORIFERA. 



Genus PROTOSPONGIA Salter. 



Protospongia chloris Walcott. 



Plate i, Figures 2, 20. 



Protospongia chloris WALCOTT, 1905, Proc. U. S. Nat. Mus., vol. xxix, p. 10. (Described and discussed 

 as a new species essentially as below.) 



Of this species only the large primary spicules are known. The skeleton is not 

 preserved. The siliceous spicules vary in size, but they all appear to be four-rayed. 

 The rays are slender, extending out usually at right angles to each other from the 

 center, but in some specimens one or more of the rays are occasionally diverted from 

 the right angle ; they slope slightly downward from the center to their extremities, 

 which gives a low, pyramidal form to the spicule; there is no trace of a central, 

 downward-pointing ray on the under side. Each ray has a rounded angle on its 

 upper side; it is slightly angular at the sides and subangular on the lower side. In 

 many examples the narrow rounded ridge of the upper side is exfoliated, leaving a 

 V-shaped groove lengthwise of the ray; the grooves from the four rays unite at 

 the center. 



As a result of the exfoliation of the upper side of the ray there appear to be three 

 forms of spicules: first, the complete spicule, as above described; second, a very 

 slender spicule with the rays rounded on the upper side and angular on the lower 

 side ; and third, a spicule having a V-shaped groove on the upper side of the rays. 



The spicules above described resemble in general form those of Protospongia 

 fenestrata Salter [1864, p. 238, plate xm, fig. 12]; they differ in the absence of the 

 central ray and the exfoliation of the upper side of the ray. A similar spicule occurs 

 in a hard shaly limestone about 200 feet (61 m.) above a white quartzitic sandstone 

 in southern Manchuria. 



59 



