24 
s. S. BUCKMAN, 
(Schwed. 
Südpolar-Exp. 
There are two series which differ conspicuously in the character of their tests. 
The first series shows coarse and distant punctae associated with a rather thick 
test, illustrated by an enlarged photograph, PI. Ill, fig. lo. The second series shows 
a finely and closely punctate test (PI. Ill, fig. i) which is also thin, as if it were a 
deep water series. Further, in the older specimens particularly, there is a sort of 
outer layer of test which is radially grooved — the groves waved and irregular 
(PI. II, fig. I d), very suggestive of the ornament seen in certain species of Lower 
Jurassic Lima {Plagiostovia). 
This finely punctate series is not punctate so finely and minutely as Terebratiila 
variabilis of the English Tertiary, which is presumably a true Terebi'atula ^ : the 
punctae of the Antarctic species are larger and therefore seem more approximate. 
There is evidently much yet to be observed and learnt concerning these differences 
of punctuation. 
The coarsely punctate series. 
The test is thick, distantly and coarsely punctate, the beak is massive and the 
foramen large — all these characters seem to indicate that the species of this series 
are shallow water forms. The condition of the test in regard to preservation is also 
quite different from that of the finely punctate series — it is somewhat decomposed, 
and roughened; yet both series occur together. 
Terebratula trinitatensis, Guppy. 
Plate III, fig. 8. 
1866. Terebratula trinitatensis.^ GuPPY, Tert. Brach., Trinidad, 296, PI. XIX, f. i. 
Description: ‘Shell smooth, gibbous, irregularly pentagonal, somewhat longer 
than wide, marked by wide, shallow and obscure sulci of growth, which become 
finer and more -distinct towards the margins; front edge nearly straight; ventral 
valve convex and rounded towards the beak, flattened towards the front edge; dor- 
sal valve convex .with an obscure carination radiating to each .angle of the front 
edge; beak large, scarcely yicurved over the dorsal valve, truncate by a rather large 
subcircular foramen, from which a wide and shallow sulcus extends forwards. 
(Guppy). 
Smooth, stout, gibbous, elongately pentagonal; marked at wide intervals with 
distinct giowth halts: they are more numerous and rather more distinct near the 
margin. Anterior margin raised to a straight single fold. Beak large, short, not 
incurved, obliquely truncate; foramen large, (circular?), labiate. 
' For a discussion of the genotype of Terebratula, and for nomenclature of English Tertiary Terebra- 
tula see the author’s papers cited in the Bibliography (6, 6 a). 
