52 
PKOBOSCIXA. 
Disteibution. 
England : 
Upper Chalk: Broadstairs ; Gravesend. 
Zone of Actinocamax quadratus : East Hamham. 
IVIiddle Chalk : Chatham. 
Foreign: 
Senonian : Biigen (fide ^larsson) . 
Cenomanian — Lower Planer : Saxony. 
Figtjees. 
PL II. Fig. 9. A zoarium encrusting Galerites aJhogalerus. 
Upper Chalk : Kent. Fig. 9«, part of zoarium with an expansion 
( ? gonoecial), X 12 dia. ; Fig. lower part of the same zoarium, 
X 12 dia. Bowerbank Coll. D. 2976. 
Affinities. 
The zoarium of this species resembles the specimen described 
by d’Orbigny as Reptotuhigera serpetis ; ^ but it differs from that 
form by the irregular arrangement of its orifices. Its serpuli- 
form zoarium also calls attention to its possible affinity to the 
P. serpulaformis (Ildm.),^ which, however, has a much broader 
zoarium and linear series of peristomes, and is possibly specifically 
identical with Prohoscma radiolitorum (Orb.). 
The ‘ species ’ is exceptionally well marked owing to its narrow, 
ridged zoarium, and the great irregularity in the arrangement of 
the orifices along this ridge. 
LIST OF SPECDIEXS. 
D. 2976. On Galerites albogalerus (Leske). Upper Chalk. Kent. Bowerbank 
Coll. Figd. PL II. Figs. 9a, b. 
D. 978. TTith Berenicea regularis (Urb.), var. ambita, Greg, (on slide). Middle 
Chalk. Chatham. Tine Coll. Eecorded as F. elevata, var., 
Tine : Rep. Brit. Assoc. 1892 (1893), p. 307, specimen Xo. 7. 
B. 805. With Actinopora Berenicea, etc., on Echinocorys scutatus, Leske. 
Upper Chalk. Broadstairs, Kent. Presented by Mrs. Burnett, 
1882. 
B. 3741. Encrusting Spinopora. Upper Chalk. Gravesend. F. Harford 
Coll. 
D. 4277. On echinid fragment. Upper Chalk: zone oi Actinocamax quadratus. 
East Harnham. Gamble Coll. 
^ D’Orbigny: Bit. Cret. p. 755, pi. 751, figs. 4-7. 
2 Rosacilla serpidceformis, Romer : Uerst. nordd. Kr. p. 19, pi. v. fig. 16. 
