340 
PACIFIC SCIENCE, VoL XVIII, July 1964 
60 ° 80 * 100 * 120 ° 
Fig. 2. Distribution of S. gazellae and S. pacifica in the Indian Ocean, including positive records from 
previous expeditions. 
vergence. In the Pacific ( Alvarino, loc. cit. ) , at 
about 35° S — 21° S, there is an overlapping 
of the populations of S. gazellae and S. pacifica 
at about 200-400 m depth. In the Indian Ocean, 
the northern boundary of S . gazellae and the 
southern boundary of S', pacifica did not overlap, 
and do not even appear well juxtaposed. How- 
ever, this pattern cannot be admitted as defini- 
tive; it may be due to scarcity of sampling in 
these localities. More data from this region will 
eventually show if this distributional pattern 
persists, or if both species occur in a pattern 
similar to that shown in the Pacific. 
S. lyra recorded by Tokioka (1940) is most 
probably S. gazellae because of the geographic 
localities of the records (33° and 35° S and 
151° E); and the S. lyra recorded by David 
(1959) and by Johnson and Taylor (1921) 
may also be S. gazellae. 
S. pacifca populations of the Pacific and In- 
dian oceans connect along the Indonesian seas 
(author’s records; Tokioka, 1955, 195 6b; and 
possibly also the report of Beraneck, 1895). It 
appears to extend with the South Equatorial 
Current to the Indonesian seas and then into the 
Indian Ocean ( Fig. 2 ) . It cannot be ascertained 
if some representatives of this species enter 
the Agulhas Current, since they have not yet 
been observed in the Atlantic. 
Previous records of S. senate dent at a in the 
Indian Ocean by Burfield and Harvey (1926), 
Doncaster (1903), Fowler (1906), John (1937), 
Ritter-Zahony (1910, 1911), and Schilp (1941), 
could be considered to be 5*. pacifica. Baldas- 
seroni (1915) was the first to distinguish At- 
lantic specimens of serratodentata from those 
of the Pacific; he gave a short diagnosis and 
published drawings of the seminal vesicles of 
the species. Tokioka (1940) published a com- 
plete diagnosis and named the species. Cleve’s 
(1901) records of S. serratodentata Krohn should 
correspond to S. pacifca. The John (1937), 
