Chilton. — Ampkipodan Genera Bircenna, Kuria, and Wandelia. 59 



Fam. CoROPHiiD^. 



Paracorophium excavatum (G. M. Thomson). 



Corophium excavatum, G. M. Thomson in Trans. N.Z. Inst., vol. xvi, p. 236, 

 ph xii, figs. 1-8 (1884). Paracorophium excavatum, Hutton in Index 

 Faunse N.Z., p. 261 (190-1). Paracorophium excavatum, Chilton in P.Z.S. 

 London, 1906, p. 704 (19<>6). Paracorophium excavatum, Stebbing in 

 " Das Tierreich Amphipoda," p. 664 (1906). 



This species was originally described by Mr. Thomson from the Brighton 

 Creek (salt water), near Dnnedin. Subsequently I took it from the same 

 creek at a time when the water was almost fresh, and specimens lived in 

 some of the same water for several months. I have also specimens taken 

 from brackish water at Napier. Messrs. Lucas and Hodgkin afterwards 

 took it near Lake Rotoiti (5 fathoms), and in Lake Waikare, where, of 

 course, the water is perfectly fresh. It therefore appears to be one 

 of several species of our New Zealand Amphipoda that are able to live 

 either in salt or in fresh water. 



So far as I am aware, it is the only known fresh-water species of the 

 family Corophiidce. 



Art. XIV. — Note on the Amphipodan Genera Bircenna, Kuria, and 



WandeUa. 



By Charles Chilton, M.A., D.Sc, F.L.S., Professor of Biology, Canter- 

 bury College, New Zealand. 



[Read before the Philosophical Institute of Canterbury, 2nd December, 1908.] 



In 1884 I established a new genus Bircenna for a peculiar small amphi- 

 pod found at Lyttelton. The genus was characterized as follows : Body 

 broad, coxae very shallow. Antennae subequal, upper without a secondary 

 appendage. Mandibles without an appendage. Maxillepedes with well- 

 developed plates on both basos and ischios. Gnathopoda equal, not sub- 

 chelate. Last segment of pleon and its appendages rudimentary. Telson 

 simple, not divided. 



One of the most characteristic points was the greatly shortened pleon, 

 the 6th segment being indistinct, and the telson (as I then thought) single 

 and undivided. 



I left the position of the genus undecided, merely pointing out that 

 in several respects it seemed to resemble Phlias, Guerin. The genus 

 remained isolated and unclassified until 1899, when Mr. Stebbing placed 

 it in the family PhUadidce — the position which it occupies in his report 

 on the Amphipoda for Das Tierreich, though the name of the family is there 

 written Phliantidce. In 1902, when examining the Crustacea, collected by 

 Mr. H. 0. Forbes at Abd-el-Kuri. Messrs. A. 0. Walker and A. Scott found 

 a small amphipod which resembled Bircenna in many respects, but differed 

 inhaving the " telson divided to the base, consisting of two subtriangular 



