582 NEW YORK STATE MUSEUM 



The species received its name from the extremely broad branches, 

 which, however, have become entirely flattened, giving them the impression 

 of having been very thick but not very firm. It is quite apparent that 

 these branches of massive ajipearance were only the basal parts of a multi- 

 ramous form, ^^'hich gradually tapered into the more delicate distal parts, 



and that the latter are retained only in exceptional 



« cases, as in the tuft on the specimen represented in 



figure 4. 

 It is doubtful whether this form can be prop- 

 erly referred to Dendrograptus with D . h a 1 1 i - 

 8u'^cu'Ie.?t7s^'p°*nSrpi?tS an US Prout as the genotype, for the branches 



Srincipal stem of specimen repro- , i? n • i ii i 



ueed on plate 4. flgiire 4, enlarged suow no trace of " deuticles or thecae, but seem 



to show arransrement of apertures. ' 



Deep kill. x5 ^^ -^^ composcd of bundles of fine tubes, opening 



without projections on the surface of a common periderm. Hall, however, 

 has expressly drawn the limits of his genus so wide as to embrace forms 

 in which the cellules "appear as simple indentations on the surface and 

 those in which they are distinctly angular with the denticles conspicuous," 

 and Hopkinson and Lapworth [1875] have referred like forms to Dendro- 

 graptus. It is however obvious that these forms difEer essentially from 

 species with projecting thecae, such as D. flexuosus. 



Dendrograptus fluitans sp. nov. 



Plate 4, flgrures 11, 12 



Dendrograptus sp. nov. Ruedemann. N. Y. State Paleontol. An. Rep't. 1902. 

 p.555 



Description. Rhabdosome small (?), consisting of thin, flexuous stems 

 which bifurcate rather irregularly and terminate in long, filiform branches. 

 Thecae narrow, three times as long as wide, closely arranged, numbering 

 16 in 10mm; apparently only a short distance in contact with each other 

 (about one fourth of their length) ; in the compressed state appearing as 

 acutely pointed, little inclined (about 20°) denticles ; outer margin concave, 

 apertural margin slightly convex, recurving, forming an angle of 48° with the 

 axis of the branch. 



