47 



long and 3.5 fi wide at its base. Appendages 

 that taper toward the ends are probably 

 broken off. 



Figured specimen. — Negative 4849; Trivoli 

 Cyclothem, maceration 11 28- J, slide 4, co- 

 ordinates, 123.2 X 59.9; body size 37.9 by 

 30.5 ix. 



Hystrichosphere 3 

 Plate 8, figure 15 



The body is subcircular, folded, and has 

 at least five appendages 15 to 18 \x long. The 

 ends of the appendages are expanded, are 

 divided into numerous subdivisions, and are 

 7 to 8 /x wide. The body is covered with 

 grana about 1 /x in diameter. 



Figured specimen. — Negative 4850; Trivoli 

 Cyclothem, maceration 1128-J, slide 5, co- 

 ordinates, 123.9 X 48.3; body size 34.0 by 

 29.5 /x. 



SGOLEGODONTS 



Although several species of scolecodonts 

 were found in some of the shales, only one 

 is illustrated. 



Scolecodont 1 

 Plate 8, figure 16 



The scolecodont has eight large dentitions, 

 from 20.8 to 8.5 /x long, and numerous small, 

 joined dentitions. 



Figured specimen. — Negative 5800; Fithian 

 Cyclothem, maceration 1170-G, slide 19, co- 

 ordinates, 129.8 X 34.9; size, 69.7 ti long. 



INGERTAE SEDIS 



Genus Centonites gen. nov. 

 Plate 8, figures 17-19; text figure 12 



The generic name Centonites is proposed 

 for microfossils, probably of plant origin, 

 having the following characteristics. The mi- 

 crofossils are composed of 5 to approximately 

 15 polygonal segments joined to form radially 

 or bilaterally symmetrical bodies, their sym- 

 metry depending upon their number and ar- 

 rangement. Most of the microfossils are flatly 

 compressed, but many are folded. Straight 

 grooves are present on one side of the body 



where the segments are joined. Elevated, 

 flattened ridges or folds occur adjacent to 

 and along both sides of the grooves but are 

 absent along the smooth outer margin of the 

 microfossils. The microfossils usually are made 

 up of an odd number of segments. The most 

 common variation consists of five segments 

 arranged in a boat-shaped pattern with two 

 small, pointed segments at one end, two 

 larger segments in the middle, and one point- 

 ed segment at the opposite end (text fig. 12) . 



FIG. 12 — Centonites symmetricus sp. nov.; dii 

 grammatic reconstruction. 



In the largest specimens two to four segments 

 in the center are almost completely bordered 

 by other segments. Along the margins of the 

 largest specimens three small indentations 

 may occur, almost equal distances apart, 

 where segments are absent. These indenta- 

 tions either have smooth edges and look al- 

 most like pores or they have uneven edges 

 as if segments had been torn out. The micro- 

 fossils are revealed under oil immersion ob- 

 jective as levigate. They are 1 to 2 /x thick. 

 The known size range is 50.2 to 123.2 ft in 

 maximum diameter. 



Type species. — Centonites symmetricus sp. 

 nov. 



Affinities. — The affinities of Centonites are 

 not known, but they are most likely of plant 

 origin, perhaps a peculiar kind of spore. 



Derivation of name. — The generic name 

 refers to the polygonal, "patchwork" {cento) 

 segments composing the fossil. 



Centonites symmetricus sp. nov. 

 Plate 8, figures 17-19; text figure 12 



Diagnosis. — The microfossils, of unknown 

 origin, are composed of several polygonal seg- 



