THE HEDEEELLOIDEA BASSLER 37 



been undisturbed by surface rugosities show that a small bulblike 

 ancestrula is followed by a very short tube, which soon commences 

 to emit branches at right angles to each other at intervals of about 

 Z% mm., and that these give rise on alternate sides to zooecia, seldom 

 over 1 mm. long, emerging at angles of usually 45°. Four zooecia 

 may be counted in 5 mm., and the usual width of both the zooecia 

 and branches is about 0.35 mm. 



Occurrence. — Devonian (Hackberry-Cerro Gordo shale): Rockford, 

 Iowa, and vicinity. 



Plesiotypes.—\J.S.l<iM. Nos. 54081, 65548. 



HEDERELLA LINEARIS (Fenton and Fenton. 1924) 



Plate 5, Figures 6, 7 



Hernodia linearis Fenton and Fenton, Strat. and Fauna Hackberry Stage, 

 Upper Devonian, p. 73, pi. 17, fig. 7, 1924. 



Although approaching Hernodia in the regularity of its budding, 

 this species seems to be a Hederella characterized by its short, broad 

 zooecia arising at regular intervals of 1.25 mm. alternately on the sides 

 of the branch at an angle of 30° or less. Branching of the zoarium 

 also occurs rather regularly at intervals of about 6}^ mm. and at 

 angles of about 60°. Measuring along an uncurved branch 3 zooecia 

 occur in 5 mm. Length of zooecial tubes 1.2 mm., width 0.35 mm. 

 The associated H. alternata of similar dimensions has less regular 

 branching and zooecia emerging at a higher angle. H. filijormis is 

 also similar in size but has very short, broad zooecia and branching 

 more at a right angle. 



Occurrence. — Devonian (Hackberry-Cerro Gordo shale): Rock- 

 ford, Iowa, and vicinity. 



PZmofi/pe.— U.S.N.M. No. 87887. 



HEDERELLA CONCINNOIDES, new species 



Plate 11, Figure 9 



A very slender species related to H. concinna, from which it may be 

 separated by its more delicate unilinear branches dividing at angles 

 of about 60° at intervals of 2.5 mm. and emitting zooecia 1 mm. 

 long and 0.15 mm. wide at an equally high angle. H. delicatula is 

 also related, but its branches are still more deUcate and not so regular, 

 while its zooecia arise at an acute angle. 



Occurrence. — Middle Devonian: 2}^ miles southwest of Sylvania, 

 Ohio (holotype) (Silica shale); 3 miles west of East Bethany, N. Y. 

 (Centerfield shale). 



Holotype.— U.S.lSi.M. No. 94585. 



