88 
PACIFIC SCIENCE, Vol. IX, January, 1955 
italia he figures (Fig. 12, p. 14) are those of 
the latter species. The genitalia of the true 
S. cookiana are quite distinctive. 
A search through the literature shows that 
the development of only six species of Si- 
phonariidae is known. These are: S. { Simphi - 
siphonaria ) zelandica Quoy and Gaimard from 
New Zealand, described by Hutton (1882) as 
S. australis Quoy and Gaimard; S. { Patellopsis ) 
pectinata (L.) from the Southern Mediterra- 
nean, described by Dieuzeide (1935) as S. 
algesirae Quoy and Gaimard; S. ( Sacculisiphon - 
aria) japonica (Donovan) from Japan, de- 
scribed by Abe (1939) as S. atra Quoy and 
Gaimard; ? S. ( Sacculosiphonaria ) cochleariformis 
Reeve from Japan, described by Fujita (1904) 
as S. lepida Gould; S. { Patellopsis ) belcher i Han- 
ley from the Persian Gulf, described by 
Thorson (1940) as S. sipho; S. {Siphonaria) 
kurracheensis Reeve also described by Thorson 
(1940) from the Persian Gulf. Of these the 
last species has a non-pelagic development, 
the others a pelagic larval stage. In addition 
observations by Borland (1949) on Benhamina 
obliquata and by myself on S. cookiana and S . 
australis indicate that these three species also 
have a pelagic larval stage. The development 
of representatives of only four of the ten 
groups into which Hubendick divides the 
Genus Siphonaria is known, and to date the 
development of the Kerguelenella group, which 
consists of four species having a circum- 
antarctic distribution has remained unknown. 
Among the species of Siphonariidae for 
which the development is known K. stew- 
artiana is notable for the size of the egg and 
the small number of eggs in the egg mass. 
Table shows a comparison of the eggs of K. 
stewartiana and three other species. 
S. {Siphonaria) kurracheensis , the other spe- 
cies with direct development, also occurs at 
or above the high water level. The species 
with a pelagic larval stage all occur below 
high water in the intertidal zone proper. 
In S' {Patellopsis) pectinata (Dieuzeide, 1935) 
and S. {Simphisiphonaria) zelandica (Hutton, 
1882) the larval shell appears to be lost and 
does not form part of the adult shell. In K. 
stewartiana as in S. kurracheensis (Thorson, 
1940) and Williamia vernalis (Hubendick, 
1946) the larval shell forms the upper part of 
the adult shell (Fig. 1 l,k). 
TABLE 1 
Size of Egg Mass, Number of Eggs, and Size of Egg of Several Species of Siphonariidae 
SIZE OF NUMBER OF EGGS SIZE OF 
SPECIES egg mass per mass egg 
K. stewartiana 12 mm. 12-25 2.00/1.35 mm. 
S. kurracheensis 12 mm. Hundreds 0.50/0.38 mm. 
S. belcheri 25 mm. Numerous 0.25/0.17 mm. 
B. obliquata 25-50 mm. 45,000-190,000 Unknown 
REFERENCES 
Abe, N. 1941. Ecological observations on a 
limpet-like pulmonate ; Siphonaria atra Quoy 
et Gaimard. Palao Prop. Biol. Sta. Studies 
2(2): 239-278. 
Borland, C. 1949. Ecological study of Ben- 
hamina obliquata (Sowerby) a Basammoto- 
phorous Pulmonate in Otago Harbour. 
Roy. SoC' New Zeal , Trans. 78(4): 285-293. 
Dieuzeide, R. 1935. Contribution a Fetude 
de deux types de gasterpodes polmones 
marins: Siphonaria algesirae Quoy and 
Gaimard; Gadinia garnoti Payraudau. Cas- 
tiglione Sta. d'Agri. et de Perche , Trav. Fasc. 
1-2: 5-196. 
Fujita, T. 1904. On the formation of germinal 
layers in Gastropoda. Tokyo Imp. Univ ., Col. 
