“Cribrimorph” Cretaceous Polyzoa. 407 
bar very thick, with a median projection ; apertural spines 
four ; secondary intercecial tissue much developed; avi- 
cularia numerous, sporadic, small, blunt, and with constricted 
apertures, growing up with the intereecial secondary tissue 
and tending to swamp the intraterminal front wall by 
forming an incomplete secondary frout wall. 
TaRACTOPORA, gen. Nov. 
Genotype. 7. confusa. 
Tabular Diaynoses of the Species. 
A. Coste about 6. 
I. Avicularia smaller and less secondary tissue.. 1. 7. confusa. 
If. Avicularia larger and more secondary tissue. 2. 7. obseurata. 
B. Coste 8-10; avicularia small and much second- 
BES CISION Bat raya ser aye orks o ores a¥e a 5 203m 0's 3. T. rostrata. 
1. 7. confusa, sp. n. 
Type-specimen. British Museum, D. 25538; low in cor- 
testudinarium-zone ; S.E. of Boxmoor, Herts. 
2. LT. [Membraniporella| obscurata (Brydone), 1916, Geol. 
Mag. dec. vi. vol. ii. p. 99, pl. vi. figs. 9-10; cor- 
testudinarium-zone; Seaford, Sussex. 
3. LT. rostrata, sp. un. 
Type-specimen. In the collection of M. Canu (a photograph 
-of the type-specimen in British Museum) ; Coniacian ; 
Fécamp, France. 
J. Thoracoporide, fam. nov. 
Multiserial Cheilostome Polyzoa of small to moderate size 
4-2 mm. in length) derived from ‘“‘ Membranimorphs”’ with 
ovate apertures; the intraterminal front wall is formed of 
few, thin, cylindrical, well-arched costz, widely separate 
laterally and hardly fused or firmly joined in a thin median 
line of fusion; apertural spines four, the proximal pair as 
large as the cost ; little or no secondary tissue developed ; 
avicularia fairly large, sporadic, with long spatulate man- 
dibles, in general shape resembling the avicularia of the 
Eleidz (eleocellaria of Canu, 1900, Bull. Soe. Géol. France, 
ser. li. vol. xxviil. p. 341). 
