S.A. NAT., 
VOL. XVIII, No. 2. 
By TOM IREDALE. 
ly.. 
Bothriembryon spenceri. 
1894. Liparus spenceri Tate, Trans. Proc. Roy. Soc. South: 
Austr., \’ol. XVIII, p.l92j November; Central Australia.. 
Figd. Rep. Horn. ScL Exped. Cent. Austr., pt. II, Zool.,- 
p.202, pi. XVIII, fig. 13, February 1896: Palm Creek.. 
Family Laomidae. 
We now come to a series of small shells, somewhat helicoid' 
in shape, not exceeding a few millimetres in width, and generally 
the height is less than the width. It is necessary to examine each, 
specimen with a good lens, and then later with a compound 
micrcscope to accurately differentiate the species. Until recently 
these were all classed together under the name “Endodontidae/^’ 
hut the student soon recognises that there are several groups with 
distinct superficies, and these are here recognised as families.. 
This course is necessary as otherwise the confusion would become- 
greater, and there is already more than enough. 
Key to Genera. 
Shell small, conical, apical whorls smooth or delicately striate,. 
umbilicus wide, sculpture of fine whorls of varying 
strength Paralaoma.. 
Shell larger, conical, apical whorls more boldly sculptured, 
umbilicus small, almost closed, sculpture more- 
regular and with interstitial cross lining. 
Excellaoma,. 
Shell more conical, apical whorls smooth, umbilicus minute, 
sculpture obsolete, restricted 
Magilaoma' 
It may be noted that these snails prefer dry situations. 
Genus Paralaoma. 
1913. Paralaoma Iredale, Proc. Mai. Soc. (Lond.), Vol. X,. 
p.380, September. 
Haplotype P. raoulensis Iredale. 
The Kermadec type has the apex smooth, and this appears 
to be the case in the East Australian species, but in the South 
Australian forms a fine concentric apical striation is seen, obsolete 
in the mainland shell, and noticeable in the island forms. In 
other cases this is regarded as of high value, but it appears- 
doubtful in this case. In order to keep the matter in review, the- 
subgeneric name Insullaoma is introduced for the Hummock Is- 
land species, riddlei. 
