THE HEDERELLOIDEA — BASSLER 

 Genus REPTARIA RoIIe, 1851 



29 



Zoarium incrusting, formed of regularly dividing parallel-edged 

 branches, composed of short, cylindrical, annulated zooecia of equal 

 length, in contact but not coalescing along their sides and proceeding 

 in the plane of their host laterally upward from a median line and 

 then gently outward. Gemmation takes place at the initial portion 



Genera of Reptarhdae 



A, B, Hederella Hall, 1881: A, Portion of the incrusting zoarium (X 2) of a typical species, H. filiformtt 

 (Billings, 1859), illustrating budding at angle of 45° and branching at nearly right angles; B, H. 

 parallela, new species (X 8), in which the tubes bud at such a low angle as to remain practically 

 In contact. 



C, Hernodia Hall, 1881: Genotype, H. humifusa Hall, 1881 (X 4); the incrusting roarlum Is character- 



ized by linear club-shaped zooecia, each budding at an acute angle from about the middle of tho 

 preceding tube. 



D, Hederopsii, new genus: Sketch of genotype, H. typicalis, new species (X 4), showing earlna within 



the tubes. 



E, Reptaria Rollfi, 1851: Small portion of genotype, R. stolonifera R0II6, 1851 (X 4); the parallel-edged 



branches formed of closely adjacent tubes, arising alternately from the basal portions of the preceding 

 ones, characterize the genus. 



F, Clonopora Hall, 1881: Fragment (X 4) of genotype, C. semireducta Hall, 1881, illustrating erect cylin- 



drical growth. 

 O, Ci/stopora Hall, 1881: Genotype, C. geniculata Hall, 1883 (X 6), much resembling Clonopora but 

 differing in the terminal constriction of the zooecial tubes. 

 (All figures except D after Hall and Simpson, 1887.) 



of the preceding opposite zooecium so that no central line of tubes 

 occurs as in Hederella (fig. 14, E). 



Genotype. — R. stolonifera Rolle, 1851. Upper Silurian, Devonian. 



HEDEROPSIS, new genus 



Similar to Hederella in form of zoarium and general zooecial struc- 

 ture, but within the tubes on their basal side there occurs a well- 

 defined longitudinal septum, joined by transverse partitions, outlining 

 two rows of compartments (fig. 14, D). 



Genotype. — H. typicalis, new species. Middle Devonian. 



