8 LAOMA. 



actual affinity to the Neozealandic genus Laoma ; both may perhaps 

 be regarded as remnants of a Palaeozoic fauna. 



The minute species of Diseus-Yike shells must all be re-examined 

 with especial reference to the characters of the jaw before a complete 

 list of the species of Punctum can be made. It is not unlikely that 

 micropleuros Paget, elachia, debeauxiana, poupillieri, aucapitaineana 

 and massoti Bgt, etc., will be found to belong here. For the pre- 

 sent it seems the wisest course to group in Punctum only such species 

 as are known to have the characteristic anatomical features of that 

 genus, leaving unexamined minute Patuloid forms in Patulastra. 



The species of Punctum live upon rotten or decaying logs in forests. 

 P. pygmseum Drap. iii, 29. P. conspectum Bid. ii, 203. 



achwerzenbachiana Calc. P. cryophilum Mts. iii, 32. 



v. minutissimum Lea. 



Genus LAOMA Gray, 1849. 



Laoma GRAY, Proc. Zool. Soc. Lond. 1849, p. 167 ; type B'ulimmf 

 (Laoma) leimonias. Phrixgnathus HUTTON, Trans. N. Z. Inst. xv, 

 p. 136, 1882 ; types H. fatua=P. celia Hutt., and P. marginatus 

 Hutt. See also HUTTON, Tr. N. Z. Inst. xvi, p. 168. SUTER, Tr. 

 N. Z. Inst. xxiii p. 92 and xxiv, p. 297. 



Shell more or less trochiform, thin, perforate or umbilicate, the 

 periphery keeled, at least in the young ; horn-colored, striped radially 

 with tawny. Aperture rhombic, provided with entering lamellae, or 

 without them; lip thin, simple. Type L. leimonias Gray, pi. 1, 

 fig. 1. 



Animal heliciform, the mantle subcentral, its edge slightly 

 reflected over the peristome ; no locomotive disc nor mucus pore. 



Jaw arcuate, composed of 20 to 24 rhombic or oblong plates 

 which are hairy-papillose and fringed at the upper and lower mar- 

 gins (pi. 1, fig. 4, L. glabriuscula Pfr.) 



Radula having the central tooth rather narrow, unicuspid (or tri- 

 cuspid), the mesocone much shorter than the basal-plate. Lateral 

 teeth wider, rectangular, with two cusps which are either subequal 

 or the inner one larger. Marginal teeth low, wide, with two short 

 cusps, becoming obsolete on the outermost teeth (pi. 1, fig. 3, L. 

 glabriweula] pi. 1, fig. 2, L. acanthinulopxis.) 



The number of teeth in a transverse row is 35.1.35 in L. wiri/uHita. 

 21.1.21 in acanthinulopyis, 26.1.26 in marina-, the last named 

 species has 110 straight transverse rows. 



