50 PROCEEDIZSTGS OF THE NATIONAL MUSEUM vol.87 



mature stage where branching occurs less often (at intervals of about 

 4 mm. and an angle of 40°), and the zooecia remain more in contact 

 with each other (budding at 20°), forming a biserial arrangement. 

 Measurements in the mature stage: Zooecia about 2 mm. in length and 

 0.6-0.7 mm. in width, with about 3 in 5 mm. Surface of tubes 

 strongly rugose. 



Occurrence. — Middle Devonian: Erie County (cotype) (Wanakah 

 shale), Pavilion and IK miles south of East Bethany (Tichenor lime- 

 stone), 3 miles west of East Bethany (Centerfield shale), IK miles 

 southeast of East Bethany (Kashong), Moscow (Moscow shale- 

 Windom member), and Canandaigua Lake and York (Ludlowville 

 shale), all in New York; Thedford and Arkona, Ontario (cotype) 

 (Widder shale) ; Thunder Bay Quarry, Alpena, Mich, (cotype) (Alpena 

 limestone) Partridge Point, 3 miles south of Alpena (Partridge Point 

 formation), 1^ miles northeast of Bay View (Petoskey formation), all 

 in the Traverse group of Michigan. 



Cotyyes.—U.S.'NM. Nos. 54082, 87916, 87950-87952. 



HEDERELLA CONFERTA (Hall. 1881) 



Plate 9, Figures 4, 5 



Ptilionella conferta Hall, Trans. Albany Inst., vol. 10, p. 195, 1883 (abstract, 

 p. 195, 1881); Rep. State Geol. New York, 1883, p. 56, 1884. 



Hederella conferta Hall and Simpson, Pal. New York, vol. 6, p. 279, 1887. — 

 Hall, 10th Ann. Rep. State Geol. New York, 1890, p. 56, 1891; 44th 

 Ann. Rep. New York State Mus., p. 86, 1891. 



Our description of this interesting species, heretofore unfigured, is 

 based upon a specimen incrusting an Orthoceras over a space of more 

 than 32 sq. cm. The general zoarial arrangement and branching of 

 the tubes are similar to that in H. aequidistans, but the strong zooecial 

 annulations in H. conferta and the greater number of tubes to a branch 

 will serve to distinguish them. Branching occurs at intervals of about 

 4 mm. and an angle of 45°, with zooecia 2 mm. in length and 0.35 mm. 

 in width and budding at 45°. 



Occurrence. — Hamilton (Ludlowville shale): Canandaigua Lake, 

 Kashong Creek, etc., N. Y. 



Plesiotype.—U. S.l>i.M. No. 54121. 



hederella CLARKET, new species 



Plate 10, Figure 3 



The type and only known specimen incrusts a Fistulipora and is 

 readily distinguished by the many rows of short tubes to a branch due 

 to their frequent budding at a low angle. Branching occurs at inter- 

 vals of 3 mm. and an angle of more than 45°, with the zooecial tubes 



