50 



and Tasmanian Crayfishes, which have forsaken the water and 

 excavate burrows in damp soil. In certain mining districts on 

 the west coast of Australia they do much damage to the artificial 

 water-courses by riddling through the banks and dams and 

 causing them to collapse. 



Although the tunnel leading to the heart of the burrow is free 

 from water, there is alwaj' s water in the circular chambers at the 

 end where the Crayfish lives. 



In a former paper it was suggested that these Crayfishes of the 

 genus Engceus are derived from the genus Parachceraps, which 

 has spread from Western Australia into the desert regions of the 

 centre and is now found in all parts of continental Australia ; 

 hut conclusive evidence is brought forward in this paper to show 

 that Engceus is derived from the South-eastern and Tasmanian 

 genus Asiacojjsis, and that its superficial resembla,nce to Para- 

 chceraps is due to convergence owing to similar habits. 



A striking peculiarity of the eight species of EngcBus is the 

 very great range of structural differences which they exhibit 

 compared with other Crayfishes, differences which are far greater 

 and concern more important characters than those which 

 distinguish genera or even families of other Crayfishes. Thus in 

 some species a gill may be entirely suppressed, in others half a 

 limb ((?. ^., the exopodite of the third maxillipede) is absent, in 

 others the flagellum of the antenniile. All these characters are 

 of the nature of degenerations, apparently incident on tlie sub- 

 terranean mode of life. Apart from these differences, the 

 species are obviously closely related and represent a monophyletic 

 group. 



A paper was communicated by Dr. C. L. Boulenger, M.A., 

 r>Z.S., dealing with the Myzostomida collected by Mr. Cyril 

 Crossland in the Red Sea in 1905, and containing descriptions of 

 three species, of which one is new. A complete account of the 

 anatomy of this form is given, as well as that of Jf. costatum 

 F. S. L; The latter species is described as possessing six pairs of 

 ventral " suckers,'* the largest number recorded in anj member 

 of the group. 



The Hon. Paul A. Methuen, F.Z.S., contributed a paper con- 

 taining the description of a new Amphipod, belonging to the 

 family Talitridte, which had been obtained in the Woodbush 

 district of Korthern Transvaah 



A paper by Mr. BnucE F. Cummixgs, communicated by the 

 Secretary, and entitled " On some Points in the Anatomy of the 

 Mouth»parts of the Mallophaga," dealt with some peculiar struc- 

 tures in the floor of the mouth-cavity of the Mallophaga, or the 

 biting bird-parasites, and knoAvn as the oesopKageal sclerite and 

 lingual glands. The " glands " are determined as cliitinous^ and 



