KUNGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 52. N:o I6. 23 
FAM. TRIGONIIDAE. 
Trigonia (Neotrigonia) uniophora Gray (PI. 1, fig. 16).'. 45 miles W. S. W., 48 
feet (8/7), 1 sp., 1. 20 mm; 60 feet (17/7), 1 right valve on a sponge, J]. 5 mm; 48 
miles W. S. W., 78 feet ("/7), 1 sp., 1. 21 mm.; 42 miles W. 8S. W., 72 feet (1/7), 
2 sps, max. 1. 20 mm. All the specimens agree with some shells sent by Mr. 
HEDLEY, as well as with figure 2a in ReEvEe (Conch. Icon. 12, 1860). This species 
was previously known only from Torres Strait and south of N. Guinea, 3—28 fms 
(E.A.Smira 1885). Mr. Hepiey informs me that is has, besides, been recorded from 
Indian Island, Bynoe Harbour, W. A., and Port Darwin, N. Terr., by Brepnai 
(Trans. Philos. Soc. Adelaide I, 1878, p. 80). 
T. uniophora Gray, var. crebrisculpta n. var. (PI. 1, fig. 17). This variety 
differs from the typical form in sculpture and colour. The former consists of in all 
28 radiating ribs, of which there are 19 in the anterior part (as far back as to the 
hinder angularity), in the furrow above it 1, and on the wing 4 ribs; above the 
last-named, there are 4 rows of isolated tubercles. On the upper parts of the ribs 
the tubercles are close-set and transversally dilated, on the under half of the shell, 
they are more distant and rounded, with smaller interstices in the same rib than 
the diameter of the tubercles. The interstices between the ribs are equal to the ribs 
in breadth. The colour is very light yellowish red. Locality: 45 miles W. S. W., 
140 feet ('?/7), 1 sp., 1. 13, h. 12.3, breadth 7.4 mm. 
A comparison with 7’. uniophora (type) as to the sculpture, shows that there 
is a considerable difference in the number of ribs in the present form and in the 
typical specimens collected at Cape Jaubert. In the last-named there are 16 (one 
specimen 15) anterior ribs, 2 (1) ribs in the furrow, 3 (4) on the wing and 2 or 3 
(exceptionally 4) rows of tubercles above them. 
In shape the present form is quite like the type. It seems to be a variety 
thereof, as the difference does not seem to be so great that a specific distinction is 
well founded. Its larger and stronger tubercles place it in about the same ratio to 
T. uniophora, as is for example 7’. margaritacea var. bednalli VeRco (1907) to its 
head form. This last-named variety »is characterized by its very compressed shape, 
its narrow ribs, its large, oblong, plate-like spines, broader at their free than at their 
attached ends, features which are exceedingly constant in the very large series ob- 
tained». In the present new variety the tubercles are swollen, not flattened. The 
new variety most resembles fig. 2b of 7’. uniphora in ReErve (Conch. Icon. 12, 1860), 
From T. strangei A. ApvAms, of which two valves were kindley sent to me by Mr. 
Hepiey, the new variety differs in having more rounded not transversally dilated 
knobs, as well as in the presence of a sinus in the posterior margin. 
' For the name Neotrigonia see Cossmann, Ann. de Paléontologie, tome VII, fase. II, 1912. 
