Mr. -W. D. Lang—Revision of the 
a. Raacunorortn#£, subfam. noy. 
Tabular Diagnoses of the Genera. 
A. Secondary aperture absent, or, if present, is con- 
fined to certain cecia only ‘(presumably involved 
in the formation of an ovicell), and the proxi- 
mal shield is formed of the apertural bar only. 
1 ie secondary aperture; all cecia alike. 
. Ends of the costee form a ne median 
seam Bie ete 
. Ends of the coste form two or more rows 
of minute solid tubercles in median area of 
fusion..... ae aor: 
II. Certain cecia only (presumably pearing ovi- 
cells) have a secondary aperture whose 
proximal shield consists of the apertural bar 
only and whose distal shield is formed of 
secondary tissue which rely the aper- 
tural spines ..... Pecee eae sis se 
B. A secondary aperture always 8 present i in all cecia. 
1. Secondary aperture with a proximal shield 
formed by the fusion of the proximal pair of 
apertural spines with a median process of the 
apertural barf wsei.a ess oon cloves Resta pasion ees 
Il. Secondary aperture formed entirely by the 
fusion of avicularia, which, growing up, re- 
place the apertural spines ........ 
©) ees 0 0) eee we s8\@ e016: [oe . sees 
eee we eee eeree . 
I. RuacHeopora, gen. nov. 
Genotype. R. suéa. 
1. Rhacheopora. 
Il. Hystricopora. 
ILI. Prosotopora. 
IV. Diancopora. 
V. Diceratopora. 
Tabular Diagnoses of the Species. 
A. Larger (more than 3 mm, long); avicularia 
somewhat pointed and tend to be directed to- 
wards the middle line of the cecium. 
I. Less secondary interccial tissue ; erect, uni- 
serial, 
a. Costee 26-28 ; 
NOSIS. Sto atiG ooo Ko emo Oboe dON 
b. Cost 30 or more; generally two avicularia 
toeach aperture= sie cae «ies wide oeaee ees 
More secondary tissue. 
. Erect, unilaminar ..... 
i. Erect, bilamimen ei st coker sate so Geese 
B. Smaller (3 mm. or less in length); avicularia 
blunter and tend to be directed upwards and 
away from the middle line of the cecium. 
I. Less secondary tissue ; incrusting, unilaminar. 
II. More secondary tissue ; erect, cylindrical .... 
about one avicularium to each 
Wee 
co pli Lo Miles: 
Vécamp, France. 
12-15, 1853, p. 
[ Semiescharipora ] obliqua (dVOrbigny), 
481 ; 
R. obiaqua. 
3. R. larvalis. 
3. R. bidens. 
4, R. incrassuta. 
5. FR. vallata. 
6. R. suta. 
Pal. France. 
Senonian ; 
