W. D. Lang — Cheilostome Polyzoa. 257 



Hapsidopora haemeri, n.sp. PL XVII, figs. 1 and 2. 

 (As a mark of respect to my colleague and former teacher, Dr. S. F. 



Harmer.) 

 Diagnosis. — Hapsidopora with comparatively large terminal spines, 

 and the spines in the proximal-lateral corners of the aperture 

 smaller than in H. arcuata ; the terminal ring makes a narrower 

 ellipse ; the avicularia are slightly slenderer than in H. arcuata. 



Type-specimen. — British Museum specimen no. D. 21673; Ceno- 

 manian, Chalk Marl, 20 ft. from the base ; Cambridge ; F. Mockler 

 Coll. 



Hapsidopora arcuata, n.sp. PL XVII, figs. 3 and 4. 

 {Arcuatus, ' arched,' in reference to the hoop-like structure proximal 

 to the aperture.) 

 Diagnosis. — Hapsidopora with very small terminal spines and 

 a very stout pair of spines at the proximal-lateral corners of the 

 aperture ; the terminal ring makes a wider ellipse ; the avicularia 

 are somewhat stouter than in H. hanneri. 



Type-specimen. — British Museum specimen no. D. 22871 ; Ceno- 

 manian, Chalk Marl, 20ft. from base; Cambridge; F. Mockler Coll. 



TrLOPORA, new genus, 

 (o TvXos, 'a knob,' in reference to the beaded termen.) 

 Diagnosis. — Asty incrusting, pauciserial and branched ; at each 

 branch an uniserial stage is nearly or quite resumed, though some- 

 times a lateral bud from an oecium of one branch curves away and 

 joins the other branch ; oecia dimorphic, with unilateral budding, 

 elliptical with tapering proximal ends, but no caudse ; termen plain 

 or with minute spines, to beaded ; extra-terminal front- wall present 

 only at the extreme proximal end of the oecium ; intra-terminal 

 front-wall a wide, depressed, proximal lamina prolonged on each 

 side in lateral terminal bevels ; aperture circular to oval ; renewed 

 cecia abundant ; avicularia small, blunt, generally one, sometimes 

 a pair placed distally and somewhat laterally to each oecium. 

 Genotype. — Tylopora lorea, n.sp. 



Key to the genus Tylopora. 



A. Termen plain, or with minute spines . . T. ligatrix. 



B. Termen beaded. 



1. CEcia shorter (about "6 mm) and blunter 



distally . . . . . . T. roivei. 



2. (Ecia longer (about *8 mm) and more 



pointed distally . . . . . T. lorea. 



Tylopora ligatrix, n.sp. PL XVII, figs. 5 and 6. 

 {Ligator, 'a binder,' invented from ligare 'to bind', from the strap- 

 shaped asty.) 

 Diagnosis. — Tylopora with a plain termen, or, if spines are present, 

 these are exceedingly small. 



Type-specimen. — British Museum specimen no. D. 29205 ; in- 

 crusting Conulus subrotundus Leske. [Turonian, zone of R. cuvieri~\ ; 

 Burham, north-west of Maidstone, Kent. Coll. Hon. B. Marsham. 



DECADE VI. — VOL. IV. — NO. VI. 17 



