468 THE AUSTRALIAN HYDROMEDUS.E, 



2. SUB-FAMILY. LEPTOGRAPTIN.-E. 

 LEPTOGRAPTID/E. Lapworth. 



Hydrosome bilateral, with irregular branches. Cells apart, just 

 touching. Sicula persistent in the axilar. The broad part 

 forming the proximal end of the Hydrosome. 



No Australian representatives of this Sub-family are known. 



3. SUB-FAMILY. DICHOGRAPTIN^E. 

 DICHOGRAPTID/E. Lapworth. 



Bilateral. Branches of regular cells, very dense, rectangular 

 Sicula persistent, its point at the proximal end of the Hydrosome. 



15. GENUS. DIDYMOGRAPSUS. McCoy. 



Only two simple branches, without funiculus : Sicula axilar with 

 the point turned upward; lower Silurian. 



87. DIDYMOGRAPSUS FRUTICOSUS. Hall, 



McCoy (1) describes this species from the lower Silurian slates 

 (Llandeilo flags) of Bird Reef, Bendigo, and many other places in 

 Victoria. 



88. DIDYMOGRAPSUS QUADRIBRACHIATUS. Hall. 



This species was described by McCoy. (2) It is found together 

 with the former species in many places in Victoria. 



89. DIDYMOGRAPSUS BRYONOIDES. Hall. 



This species was described by McCoy (3) from many places in 

 Victoria. 



90. DIDYMOGRAPSUS OCTOBRACHIATUS. Hall. 



This species occurs together with the former in several places in 

 Victoria (4.) 



(1.) McCoy. Proclromus of the Paleontology of Victoria. Decade 1, 

 p. 13, pi. I. 



(2.) McCoy. (l.c), p. 15, pi. II. 



(3.; McCoy. (I.e.), p. 16, pi. II. 



(4. J McCoy. (I.e.), p. 17, pi. II. 



