690 APPENDIX L 
elliptical, crossed on the lower half posteriorly by a few (four or five) vertical lines, the 
transverse strie strong and neat. Posterior muscular See a little excavate with 
neat transverse markings.—Length 13 inches; height 85 L.; thickness 27, L.; apical 
angle about 100°.—Plate 4, fig. 1, 1 a, shell, natural size; 6, c, d, different views of cast ; 
e, larger anterior muscular impression ; /, smaller SHUEEOr) g, posterior. 
Wollongong Point, District of Illawarra. 
The proportions of this species; its beak thrown a little forward in the exterior shell 
as well as cast, so that in the latter the profile of the front below it is strongly concave ; 
the anterior muscular impressions, and especially the abrupt depression (in cast, abrupt 
elevation, of half a line) at the upper side of each larger, are striking peculiarities of this 
species. The lateral surface of the beak in the cast is flattened, and this flattened area 
extends evenly to the large muscular impression. The anterior part is hardly more than 
one quarter the whole length, while it is one-third in the eyprina. 
Astartila cytherea, Exped. Foss., Amer. Jour. Sci., ii. Ser., iv. 155. 
Pachydomus? pusillus, [7] M’Coy, loc. cit., p. 302, pl. 16, figs. 1, 2. 
25, AsTartita potiTa (Dana).—Rather thin, somewhat longer than high. Exterior 
surface smooth and shining, with faint concentric lines. Valves thin, Muscular impres~ 
sions very slightly excavate, palleal faint. Large anterior muscular impression with 
transverse striz, but none vertical—Length 1 to 17 inches; height 3;45 L.; thickness 
795 L.; apical angle 114°.—Plate 4, figs. 2, a, 6, c, natural size. 
Black Head, District of Illawarra. 
The shining exterior and thinness of the shell are peculiar, and its texture in the speci- 
mens seen was usually rather soft and dark olive-green in colour, like a compact chlorite. 
The lateral surface of the beak in the cast is flattened, nearly as in the cytherea. 
Astartila polita, Exped. Foss., Amer. Jour. Sci., ii. Ser., iv. 155. 
26. 
AsTARTILA CycLas (Dana).—Rather thin, a little longer than high, nearly equi- 
lateral, apical angle large. Exterior surface marked unevenly with irregular concentric 
strie. Anterior muscular impression strongly excavate; larger suborbicular, without 
vertical striee ; smaller narrow oblong. Posterior muscular impression mane excavate, 
—Length 13 inches; height °°, L.; thickness 43, L.; thickness of cast ;4°, L.; apical 
angle of shell 135°,—Plate 4, fig. 3, 3 a, views of shelf, natural size; b,c, cast; d, large 
anterior muscular impression, (from cast,) with commencement of palleal; e, posterior 
muscular impression. 
Wollongong Point, District of Illawarra. 
This is the thinnest of the species obtained. The beak of the cast is very thin, and 
the flattened area distinct; the surface between this area and the muscular impres- 
sion in the cast is flattened or slightly concave. The cast has the margin very thin, as 
in the eyprina. ‘The smaller anterior muscular impression is vertical, and faces very 
obliquely inward. The palleal impression is very distinct. The anterior portion of the 
shell zs more than a third the whole length. 
Astartila cyclas, Exped. Foss., Amer. Jour. Sci., i1. Ser., iv. 155. 
27. ASTARTILA TRANSVERSA (Dana).—Thick, oblong, (length one-third greater than 
height.) Posterior muscular impression faint; larger anterior subelliptical, somewhat 
excavate, without vertical strize; smaller obliquely excavate, sigmoid.—Length of cast 
