LAOMA. 



Distribution : All of the species known to belong to this genus 

 inhabit New Zealand and Tasmania. Two sections may be distin- 

 guished : 



Section Laoma Gray, s. str. Aperture provided with an entering 

 lamella upon the columella only, or with lamellae upon columella, 

 parietal wall and outer and basal lips (pi. 1, fig. 1, L. leimonias). 

 The writer has examined specimens of all of the species ; L. pcecilo- 

 sticta froms a transition to Phrixgnathus. 



Section Phrixgnathus Hutton. Shell and animal the same as in 

 Laoma, except that the aperture has no teeth or folds within. (Type 

 L. celia Hutt., pi. 1, fig. 10). This name cannot be used in a generic 

 sense on account of the priority of Gray's Laoma. The mere 

 absence of aperture-teeth is, of course, not sufficient for generic dis- 

 tinction. 



The fibrous jaw, composed of rhombic plates bound together by 

 a thin membrane only, and the peculiar bicuspid side teeth, agree 

 exactly with the genus Panctum ; and upon these grounds the two 

 genera were associated by the writer, forming the group Polyplaco- 

 gnatha (Proc. Acad. Nat. Sci. Phila. 1892, p. 403.) 



(Section Laoma Gray.) 



L. leimonias Gray, iii, 68. 

 L. poecilosticta Pfr. iii, 68. 

 pcecilocostata Pfr. olim. 



L. marina Hutt. viii, 57. 



nerissa Hutt. 

 L. pirongiaensis Sut. 



Section Phrixgnathus Hutt. 



L. marise Gray.'iii, 37. 



umbraeulum Pfr. 

 L. conella Pfr. viii, 58. 

 L. ariel Hutt. viii, 59. 

 L. marginata Hutt. viii, 60. 

 L. celia Hutt. viii, 60. 

 L. regularis Pfr. iii, 37. 

 L. erigone Gray, iii, 37. 



heldiana Pfr. 



L. microreticulata Sut. viii, 63. 

 L. pumila Hutt. viii, 63. 

 L. raricostata Sut. viii, 100. 



L. allochroida Sut. viii, 63. 



v. sericata Sut. viii, 64. 



v. lateumbilicata Sut. viii, 64. 

 L. campbellica Filh. 

 L. phrynia Hutt. viii, 61. 

 L. fatua Pfr. 



L. glabriuscula Pfr. iii, 37. 

 L. sciadium Pfr. 

 L. titania Hutt. viii, 62. 

 L. haasti Hutt. viii, 62. 

 L. acanthinulopsis Sut. viii, 61 

 L. transitans Sut. viii, 59. 



