BY C. HEDLEY. 161 



PsYRA, Hutton (1884). 



" Shell imperforate or narrowly umbilicated, ribbed, periphery- 

 rounded, not hairy. Jaw and teeth as in Charojm." 

 First species (type X) P. dimorpha, Pfeifler. 



Therasia, Huiton (1884). 



"Shell conoidal, depressed, periphery subcarinated, subperforate 

 or narrowly perforate, whorls smooth, striated or with membranous 

 plaits. Jaw with flat ribs. Margiiaal teeth broad, usually with 

 several points." 



First species (type 1) T. celinde, Gray. 



Seeing that the type of Thalassia is subrugata, Pfeifler, I must 

 decline for the present to follow Hutton in classing it (oj). cit. 

 p. 203) among the Charopidce. 



Possibly Gray's genus Laoma (1849), type L. Uimonias, Gray, 

 may be inserted in the family under discussion, but it does not 

 share the ordinary appearance of its members. 



Probably these two genera may also be included : — 



Thera, Hutton (1884). 



" Animal and jaw as in Patida. Shell conical, high, perforate, 

 hairy ; periphery angled" (op. cit. p. 193). 

 First species (type 1) T. alpha, Pfeifler. 



Phacussa, Hutton (1884). 



" Shell depressed ; periphery rounded ; whorls 5-6, gradually 

 increasing. Mantle included. Jaw with flat ribs" (op. cit. 

 p. 205). 



First species (type ?) P. hypopolia, Pfeifler. 



Suter proposed, but did not formulate, a group (genus 1) — 

 Maoriana, Trans. N.Z. Inst. 1890, p. 96 — to replace Iluttonella 

 (preoccupied) and to comprehend leioda, Hutton; pseicdoleioda, 

 Suter ; wairarapa, Suter ; hectori, Suter ; microundidata, Suter ; 

 and aorangi, Suter. He also quoted (op. cit. p. 90) Simplicaria, 

 Moiisson, as a MS. generic term. Dr. von Martens has proposed 

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