VIII ILLU.STRATIONS. 



Page. 



Fi SIS. 19, 20. — Dictyoiienm retiforiiie Hall. A siumU rhabdosome showiug 



the central portion and a portion of a larger specinieu 19 



21,22. — Dictyoneuia c'rassibasale. new species. Two rather small 



rhabdosoiues showing the proximal portion 20 



23. — Dictyonema crassibasale. new species. A compi'essed infundi- 



buliform rhabdosome 21 



24. — Dictyonema crassibasale, new species. A compressed, fragmen- 

 tary rhabdosome 22 



25. — Dictyonema crassibasale, new species. Khabdosome preserving 



the fibrous proximal i)ortiou and showing the thecte 23 



26,27. — Dictyonema polymorphum (iurley. 2(>. lihabdosome retain- 

 ing disk (plesiotype) ; 27, A compressed specimen (holotype) 

 with central portion 24 



28. — Dictyonema polymorphnm GurJey. One of Spencer's types of 



Calyptograptus snbretiformis. (After Spencer) 25 



29. — Dictyonema ])olymorphum (iurley. Spencer's figured type of 



Dictyonema tenellum. (After Spencer) 26 



30,31. — Dictyonema subretiforme (Spencer). 30, One of Spencer's 

 types of Calyi)t()grai)tiis snl)retiformis. (After Spencer) ; 31, 

 A large expanded rhabdosome from the Rochester shales of 

 New York. (Copied from Ruedemann) 27 



32,33. — Dictyonema tenellum Spencer. 32. A small example i)reserv- 

 ing the l)asal portion (by R. S. Bassler) : 33, A larger rhab- 

 dosome 29 



34,35. — Dictyonema stenactinotimi, new species. 34, Holotype; 35, 



A rhabdosome referred somewhat doubtfully 30, 



.36. — Dictyonema ex]);insum Spencer. The original type. (Copied 



from Spencer) 32 



37. — Dictyonema expansum Spencer 33 



38,39. — Dictyonema filiramus, new species. Two small rhabdosomes_ 34 



40. — Dictyonema filiramus, new species. A rhabdosome of medium 



size 34 



41-43. — Dictyonema desmoides. new s|)ecies. 41, The holotype, a 

 small but rather complete rhabdosome (by R. S. Bassler) ; 

 42. 43, Paratypes. Two fragmentary rhabdosomes 35 



44. — Dictyonema percrassus. new species. A fragmentary rhabdo- 

 some 1 35 



45. — Dictyonema percrassus, new species. Rhabdosome with basal 



attachment 36 



46. — Dictyonema spencerl. new species. Holotype 37 



47. — Dictyonema parallelum, new species. Holotype 37 



48. — Calyptograptus cyathiformis Spencer. Copy of Spencer's figure. 39 



49. — Calyptogra](tus micntnematodes Spencer. Copy of Si-encer's 



figure 39 



50. — Calyptograittus micronematodes Spencer. Plesiotype in Spen- 

 cer collection 40 



51. — Calyptograptus? radiatus Spencer. Copy of Spencer's figure__- 40 



52. — Rhizograptus bulbosus Spencer. The type-specimen. (After 



Spencer) 41 



53.— Odontocaulis granti (Spencer). A rhabdosome and a branch 



of same enlarged. (After Spencer) 43 



54. — Odontocaulis granti (Si)encer). An incomplete rhabdosome— 43 



