352 Mr. O. A. Sajce on a 



types of tliat order, it has marked affinities with the 

 Euphausid, and to a less degree witli the Mysid type, as 

 well as having a strong likeness to the primitive forms of 

 Isopoda and Amphipoda. 



Considering the stalked eye as a primitive character and 

 dominant throughout the main stem of descent of the crusta- 

 ceans, and the sessile-eyed forms as a lateral divergence, it 

 appears to me that the present form is an early stage of such 

 divergence. 



It will not be disputed that the present species in general 

 form and structure is like Anaspides tasmanim^ G, M. Thomson, 

 a noteworthy species in freshwater pools on the summit of 

 Mt. Wellington, Tasmania, and in Lake Field, situated 

 40 miles from the above situation, at an elevation of about 

 4000 feet. 



Anaspides differs from other Schizopods in possessing no 

 vestige of a carapace, and has eight distinct thoracic somites. 

 The present species has marked affinities with it, but differs 

 in a good many minor characters and fundamentally in the 

 eyes being sessile, there being no antennal scale, and in the 

 coalescence of the first tiioracic somite with the head. 



I'he loss of stalked eyes, carapace, and scale-like exopodite 

 on the antenna — each, I think, acknowltdged as primitive 

 features — while in most other respects quite of a Schizopod 

 type, marks the present species as the most primitive sessile- 

 ejed Malacostracan at present known, and it is no doubt a 

 very ancient type. I may also note that Caiman has shown 

 that Aiiasjndes closely resembles some of the oldest fossil 

 Malacostraca [Uromctes &c.). 



Specimens were collected from small freshwater reedy pools 

 beside a tiny little runnel which joins the Mullum MuUum 

 Creek, Ringwood, near Melbourne, during an excursion of 

 the Nature iStudy Class for teachers, under the direction of 

 Mr. J. A. Leach, M.Sc, to whom I am indebted for specimens. 



Order Anaspidacea, Caiman, 190L 



This order, so far, has not been defined. 



Body generally slender, of nearly cylindrical form, integu- 

 ment thin. Carapace absent. ^Jlioracic somites distinct or 

 with the anterior one fused with the head. Abdomen of 

 about equal length to the cephalon and thorax combined ; 

 somites distinct, flexing evenly throughout. P^yes stalked or 

 sessile. Antennary scale small or absent. Auditory organ 

 at base of first antenna. Peduncle of second antennge 

 four-jointed. Mandibles without a secondary cutting-edge 



