H. Bolton—A New Species of Fossil Cockroach. 147 
denticles, and surrounded by a narrow front wall which is deep-set at 
the head of the cell, and rises steadily towards the foot ; in the centre 
of the cell the bounding walls are bent rather sharply inwards to the 
edge of the aperture and back again; these avicularia have a strong 
general resemblance to those of Jf. envigilata, but it will be observed 
that the denticles in I. angusformis and I. sagittaria, being processes 
from the margin of the aperture, are not analogous to the denticles of 
M. invigilata, which are processes from the bounding wall. 
Found only at Trimingham. 
Mempranipora Laner,' nov. Pl. XIV, Figs. 9 and 10. 
Zoarium unilaminate, always encrusting. 
Zoecia often large, but very variable; length of area ‘43 to °7 mm., 
with °65 mm. asa fair mean in good specimens ; breadth -32 to -5mm., 
with -45 mm. as a similar mean; boundaries clearly marked owing to 
differences of level between adjoining zocecia but not by any furrow. 
Owcia long and rather straight-sided, often projecting slightly 
over the area of the succeeding zocecium, and generally rising from 
a slight protrusion of the margin of the aperture ; in one zocecium in 
Fig. 9 the protrusion has been formed, but no ocecium has developed 
from it. 
Avicularia of one type (vicarious) only, rather low-lying, and 
forming the initial cells of new rows of zocecia; elliptical, with wide 
elliptical apertures surrounded by a fairly wide front wall at the head 
of the cell and by a narrower one at the foot, but overhung considerably 
in the middle by the very symmetrically inbent edges of the bounding 
walls, which present the outline of an hour-glass. 
Found abundantly at, Trimingham, occasionally in the Cromer— 
Weybourne Chalk, and once in the Act. guadratus Chalk of Hampshire.” 
EXPLANATION OF PLATE XIV. 
(All figures x 11 diam.) 
MUembranipora sagittaria, zone of M. cor-anguinum, Gravesend. 
Ditto, zone of Act. guadratus (lower part), Hants. 
Ditto, zone of Act. quadratus (upper part), Hants. 
M. dolium, zone of Act. guadratus (upper part), Hants. 
Ditto, zone of B. mucronata (?), Bramford, Suffolk. 
Ditto, Cromer-Weybourne Chalk. 
M. anguifor mis, Trimingham. 
Ditto, Trimingham (another specimen). 
M. Langi, exceptionally preserved, Trimingham. 
Ditto, in ordinary preservation, Trimingham. 
SD OAD OV Co bo 
a 
It. — On a New Spectres or Fosstn Cockroacu, -ArCHIMYLACRIS 
(ZrostatTtina) Woopw4kpi, From THE SourH Waters CoAL-FIELD. 
By Herzerr Botton, F.R.S.E., F.G.S., of the Bristol Museum of Natural History. 
(PLATE XV.) 
(V\HE Orthopteron wing which forms the subject of the present 
paper was obtained by Mr. David Davies from a dark-blue shale, 
about 10 feet in thickness, overlying the No. 2 Rhondda coal-seam in 
1 Dedicated to W. D. Lang, Esq., of the British Museum (Natural History). 
2 Erratum: p. 76, 1. 29, for construction read constriction. 
