52 TRANSACTIONS OF THE ROYAL CANADIAN INSTITUTE. [VOL. XI 
BARRANDELLA (?) MESOPLICATA, Sp. nov. 
Plate III, Figures 8, 9 and Io. 
Three imperfect casts of a small shell having a length of 11 mm. and 
a width of rather less than 10 mm., also another specimen probably of 
the same species but with a greater proportional width. 
Both valves are prominently convex, with a beak of the larger valve 
incurved; it is probable that the shell would show scarcely any interval 
between the beaks. The umbonal region is smooth in both valves, but 
towards the anterior margin a broad sinus is developed in the larger 
valve marked in the centre by a rather sharp rib. Outside the more 
prominent ribs bordering the sinus are single, short, and faintly defined 
ribs. The corresponding crenulations on the smaller valve are rather 
less prominent. The greatest width of the shell is anterior to the mid- 
length and the outline of the larger valve is sub-trigonal. This valve 
is rather fiat in the mid region, but the smaller valve is sharply convex 
with slight concavities towards the lateral margins. 
With no knowledge of the interior, it is manifestly impossible to 
ascribe this species to its proper genus. The external appearance sug- 
gests a Merestelloid, Camarelloid, or Pentameroid shell. I am inclined 
to provisionally place the species under the latter type in the genus 
Barrandella. The form is remarkably like Sieberella nucleus, Hall and 
Whitfield, but in Sieberella the sinus is on the brachial valve. On this 
interpretation the larger valve is of course the pedicle. The specimens 
also suggest the genus Parastrophia, but they are probably too elongate 
for that genus. If the interior should reveal a Camarelloid structure 
the species should probably be removed to Parastrophia, in which case 
the larger valve is the brachial. 
Locality—Assina rapids, Severn river, District of Patricia, Ontario. 
Horizon—Silurian. 
No. 399 S. Royal Ontario Museum of Palaeontology. 
SPIRIFER CRISPUS, Hisinger sp. 
TEREBRATULA CRISPA, Hisinger. Act. R. Acad. Sci. Holmiensis, tab. VII, fig. 4, 1826. 
JEREBRATULA CRISPA, Histnger. Idem. Anteckn. IV, tab. VII, Fig. 4. 
DELTHYRIS CRIsPUS, Dalman. Vet. Acad. Handl., p. 122, tab. 3, fig. 6, 1827. 
DELTHYRIS CRIsPUS, Hisinger. Petref. Suecica, p. 73, t. X XI, fig. 5a and 5b, 1839. 
SPIRIFER CRISPUS, Sowerby. Murichson’s Sil. Syst., p. 624, pl. 12, fig. 8, 1839. 
DELTHYRIS STAMINEA, Hail. Geol. Rep. 4th Dist., N. York, p. 105, fig. 3, and p. 106, 
1843. 
SPIRIFER CRISPUS, Hail. Pal., N. York, Vol. II, p. 262, pl. LIV, figs. 3a-k, 1851. 
SPIRIFER CRISPUS (?), Whiteaves. Geol. Sur. Can., Palaeoz. Foss., Vol. III, pt. IV, p. 253, 
pl. 27,,, fig. I, 1906. 
