372 Proceedings of the Royal Physical Society, 



strong Squilla-like characters, and forms the centre of a new- 

 family group of Stomatopoda, there being evidently several 

 undescribed species in the collection. Anthrapalcemon 

 Traquairii, Peach, is partly founded on a specimen belong- 

 ing to the above Squilla-like family, and partly on a 

 specimen showing strong Thysanopod characters. 



From the study of material presented to the Geological 

 Survey by Mr Wm. Anderson, collected by him from the 

 bed at Ardross from which the Eev. D. Brown obtained the 

 original specimens, Crangopsis {Pala^ocrangon) socialis, Salter, 

 appears to have all the characters of a Thysanopod, and must 

 be placed under the Euphausiidae. Several other forms 

 belonging to the Euphausiidae also occur in the Geological 

 Survey collection of Carboniferous Crustacea, and it seems 

 to me that it is from this branch that the Decapoda descend, 

 but I have not met with the remains of a single true 

 Decapod. Palmocaris, as already indicated, is a transitional 

 form between the Schizopoda and Isopoda or Amphipoda. 

 In 1896, W. T. Caiman read a paper before the Eoyal Society 

 of Edinburgh on a recent Crustacean found in a fresh-water 

 lake in Tasmania, which he named Anaspides, as it has all 

 its body segments free, and bears no carapace, and though 

 being most nearly allied to the Schizopods has affinity with 

 the Amphipods, It combines many of the characters of 

 Palceocaris, Meek and Worthen, and Gampsonyx, Jordan, 

 a genus of Crustacea found in the permo-Carboniferous rocks 

 of Saarbriick.^ Kingsley puts Pygocephalus and Crangopsis 

 (Palceocrangon), Salter, among the Schizopods, and he con- 

 siders that Anthrapalcemon and Pseudogalathea are more 

 nearly allied to the Schizopods than to any other forms, an 

 opinion with which I heartily agree.^ 



From the occurrence of so many transitional forms in the 

 Lower Carboniferous rocks, it would appear that the Schiz- 

 opods were dominant in Carboniferous times, and that they 

 were giving off several branches, the Isopods on one side, the 

 Decapods on another, and the Stomatopods on a third line 



W. T. Caiman "On the Genus Anaspides,'! Trails. Roy. Soc. Edin., 

 vol. xxxviii., 1896. 

 ® Eastman's translation of " Zittel's Palaeontology," p. 659, 1900. 



