22 
in fine acute free spines. The costie on oiii* best preserved specimen number 
eighteen, and are all primary ; the latilaminm are well developed and 
overlapping. Tlie impression of the hinge-plate is linear and long. 
Locality and Horizon. — Torryburn Station, twelve miles from Paterson 
{IV. II. II. Yarrington and J . Carboniferous. 
Collection. — Mining and Geological Museum. 
DELTOPECTEX, Eth.fil., 1892. 
(Geol. Pal. G’land, itc., 1892, ji. 269.) 
Observations. — The hinge mechanism of this genus is well displayed 
in one of our specimens of I), lenimculns, Dana, sp. (PI. VII, Pig. 2). This 
is a testiferous example exhibiting a wide gape between the hinge-plates 
of the two valves left by the absent rcsilium, and bearing its furrows 
of attachment, with tlie central suhumbonal chondrophore. It is in the 
possession of the latter that Deltopectcn differs from Avicidopecten, and 
thus occupies an intermediate position between the latter and Lecten 
proper; in other words, it possesses the hinge structure of both genera. 
Fernopecten, IVinchell, according to Jlall,^ has a “central cartilage pit,” 
but the rcsilium furrows replaced by “ crcnulations ” on each side of the 
former below the hinge margin. Again, Crenipecten, Hall, 2 >ossesses the 
“same cartilage pits througliout its [the hinge-plate] entire length.” 
Deltopecten lim.pformis, Jlorris, sp.- 
( Plate X, Pigs. 3 and d ; PI. XI, Pigs. 1 and 2.) 
Fecten linKcfonnis, Morris, .Strzelecki’s Phys. Descrip. N.S. Wales, etc., 1845, j>. 277, t. 13, f. 1. 
Observations . — Morris figured a right valve, decorticated except on tlie 
auricles, and the interior of the same. He described the shell as suborlncular, 
oblique, and inequilateral, with numerous irregular costic, and the auricles 
rather small and wrinkled. A glance at the figure will show that the latter 
are definitely radiate, and the costm approximately thirty-four in number — 
Morris says thirty-six. 
' Hall — Pal. New York, 1S84, V, Pt. 1, No. 1, p. xii. 
^ Non A. Umiformis, White and Whitfield. 
