251 
PTEROPODA. 
Genus Hyolithes, Eichwald, 1840. 
(Sil. Schich. Syst. in Ehstland, 1840, p. 97.) 
Hyolithes communis, Billings. 
Ohs. — This genus is represented by single small tubes up 
to twenty-five millimetres in length, but without other dis- 
tinctive characters. I have not seen any trace of an operculum. 
The facies of the specimens is that of //. communis, Billings, 
already recorded from the Parara limestone at Curraniuika 
by the late Professor R. Tate. 
DESCRIPTION OF PLATE XXV. 
Olenellus, sp. 
Fig. 1.— Incomplete cephalon. showing the glabella, palpe- 
bral and eye lobes, etc. — x ^- * 
Obolella wirrialpensis, Efli. jiJ. 
Fig. 2. — External view of a nearly complete nedicle (?) valve 
— X 3-. 
Fig. 3. — Imperfect internal cast, exhibiting traces of muscu- 
lar scars — X 3. 
O. WIRRIALPENSIS, var. calceoloides, Efli. fil. 
Fig. 4. — External view of a flask-shaijed pedicle (?) valve- — 
x3. ^ 
Fig. 5. — Side view of another specimen — x 3. 
Fig. 6. — Umbonal view of the same — x 3. 
OrTHIS (y) TATEI, Eth. fiJ. 
Fig. 7.-— Pedical valve with tliick, radiating eostse on the 
median portion of the valve — x 2. 
Fig. 8. — A similar specimen — y 2. 
Orthis ( vel Orthisina), sp. 
Fig. 9. — Snbqnadrilateral pedicle (?) valve, with a moae- 
rately deep sinus, bounded by ill-defined folds — x 3. 
Orthis ( ctJ Orthisina), sp. 
Fig. 10. — Kotundo-quadrate brachial (?) valve, with a pinch- 
ed-up fold — X 3. 
