FOSSILS OF THE ST. LOUIS GROUP. 535 



leaving a gaping suture between them and the seeoiid 

 rndiuls. Second radials wider than high, except the ante- 

 rior one, which is narrower, and is succeeded by three 

 more short sub-radials, the upper one of which gives off 

 two arms, which bifurcate again on the eighth plate above. 

 In the other four rays the arms start from the opposite 

 sides of the .second radials and bifurcate first on the sixth 

 plate, and again on the eighth and sixteenth plates above. 

 Indications of rather indistinct nodes are to be seen on the 

 plates of the body, as well as on the lateral sides of the 

 amis. The upper extremity of a comparatively large ventral 

 tube is to be seen on one side of the specimen, the diameter 

 of which at the summit is about equal to the diameter of 

 the body at the top of the first radial plates. The plates 

 forming the summit of this ventral tube, or proboscis, are 

 produced into nodes and short spines. 



Position- and locality St. Louis Limestone ? near Huntsville, Ala- 

 bama. 



ZEACRLSTS CARIXIFEROUS, TTorthen Ms. 



PL 20, Fig. 4. 



BODY small, depressed basin-shaped, or about three times 

 as wide as high to the top of the first radials: base concave 

 and hidden bv the column; subradials about as wide as 







high, three hexagonal and two heptagonal; first radials 

 short, more than twice as wide as long, with a sharp carina 

 extending quite across their upper margins, and joined near 

 the middle by two similar ones coming up from the lower 

 margins of each plate, thus dividing the surface of each 

 first radial piece into three nearly equal triangular spa< 

 Src-ond radials about two-thirds as long as wide, and orna- 

 mented like the first radials with a carina across their lower 

 margins, and a similar one extending upward in the center 

 of the plate nearly to the acute upper angle. First and 

 second radials pentagonal as far as can be seen. Anal 



