Tate— List of Irish Liassic Fossils. 
i8 
cancellated by very fine oblique striae. Siphonal band very narrow, occupying 
a slight depression on the upper carina, ornamented with three longitudinal 
striae. Base imperforate, concentrically striated ; aperture subquadrangular. 
Dimensions.— Total length, -9 inch ; breadth of last whorl, ’6 inch ; height 
of last whorl, - 4 inch. 
P. Tectaria cannot be confounded with any Liassic species of the genus, 
though related to P. subtilis , Deslong. It resembles in figure, several Palaeozoic 
forms, and especially P. tornatilis , Phil., from the Carboniferous Limestone. 
Geological Position. — Zone of A. angulatus , between Garron Point and 
Red Bay, two examples fi?. T. ) ; Island Magee, one example (S. A. Stewart). 
12. — Hinnites angularis, nov. spec., Plate I. fig. 2. 
Shell inequivale, subinaequilateral, thick, left valve convex, transversely 
oblong; umbo subacute, not extending beyond the hinge line, which is moderately 
arched; ornamented with crowded radiating ribs, unequal, obtuse, the surface 
of which is raised into spinous squamae, and alternating irregularly with smaller 
and similarly ornamented costae; costae of umbonal region without spinous 
nodulations. Five or six of the radiating costae are much stronger than the 
others, and somewhat regularly disposed, giving a polygonal outline to the 
valve. Ears ornamented as the rest of the shell. Right valve ornamented 
as the other valve. Breadth 2-5 inches, length 2 inches. 
H. angularis agrees with Lima nodulosa, Terq., in the radiating spiniferous 
ribs, alternately large and small; but differs in the absence of rugous, serrated 
concentric stria, and in its greater gibbosity, oblong figure, inequivalve character, 
and by the polygonal outline given to it by the larger ribs. 
Geological Position.— Zone of “A. angulatus,” Island. Magee, two ex- 
amples {R. T.); lowest beds of Lower Lias, Laleston, S. Wales. {P. Etheridge ), 
Coll. Brit. Museum. 
13. — Avicula Pattersoni, nov. spec., Plate I. fig. 10. 
Shell dfepressed, ovate, transverse, slightly oblique, concentrically striated; 
anterior margin arched, and superiorly sinuated; hinge line straight; anterior 
wing very short, acute; posterior wing elongated, acuminated, excavated behind. 
A. Pattersoni has a general resemblance to Gervillia crenatula, Quenst., 
which the author states distinctly to possess cardinal pits, and as the type 
specimen of this species displays a single extended cartilage pit, it cannot be 
referred to that genus. It has much analogy with A . Deshay esi, Terqm., but 
is much less oblique, has a smaller anterior wing, and an acute umbo, not being 
so concave a shell as that species. This species was referred by Portlock to 
A. Goldfussi. Several specimens from Craig and Gortmore form part of the 
Portlockian collection. The figured specimen I obtained from the Zone of 
11 A. angulatus” at Island Magee. 
The species is dedicated to my kind friend Robert Patterson, Esq., F.R.S. 
