of till' Jiirussic Bi'ijozna. 225 



ilichotomously or irregularly, and sonu'tiiiu's anastomose into 

 a reticular wel). The peristome is tliisii or sliglitly raised. 

 Zocecia tubular or suhpyritbrm. 



'J'ype species : S. dichotomu (Lamnuroux ). 



1. Stomatopora dichotoma (Lamx.), 



Alecto dichotoma, Lnniouroux, 1821, Kxp. iii»5tli. I'olyp. p. 84, pi. Ixxxi. 



tigs. 1L>-14. 

 Stoiiuitoporn dichotoma, IJroiin, ISL'*), I'lianzenth. ])p. 27, 48, pi. vii. 



tif.'. .'i. 

 AitlojHira dichotoma, (Joldfiiss, 1831, Petref. Cierni. VA. i. p. 218, 



pi. Ixv. tig. 2 (y iU)U 2 a). 

 Stomatopora antiqua, Ilaime, 18'j4, M(5m. Soc. jr6ol. France, ser. 2, 



t. V. p. I(i2, pi. vi. tig. 7. 

 Stomatopora Haimei, Terq. & Piette, 18Go, ibid. st5r. 2, t. viii. p. 124, 



pi. xiv. Hg.s. lS», 30. 

 Stomatopora di/afan.-- jiioutlivalti/tn'iitis. Vine, 1883, Kep. Hiit. As.soc. 



1882, p. 201. 

 Stoviato/Hira Terqiicmi, Ilaime. I8;j4, oj). cit. p. 164, pi. vi. tig. 4. 

 Stomafiij)i>ra M'a/tioii {non Ilaime), Vine, 1884, Quart. Journ. Geo]. 



Soc. vol. xl. p. 787. 

 Stomatopora spirata, Walford, 1889, ibid. vol. xlv. p. .')G4, pi. xviii. 



tig. (!. 

 Stomatopora parrecta, Wah'ord, 188!>, ibid. vol. xlv. p. -'tiV), pi. xviii. 



tigs. 7, s. 



Diagnosis. — Zoarium typically forming a locse irregular 

 network ; the lines radiate from the centre and repeatedly 

 branch dichotomously. Eiglit or ten zocecia m.ay occur 

 between two points of bifurcation. Such series are often 

 curved (var. spirataj Waif.). Young forms consist of a 

 single line, which may at first branch very sparingly (var. 

 porrecta, A\'alt.). Crowded growths occur. 



Zocecia regularly cylindrical. 



Peristomes well raised, varying in height from lialf to one 

 and a hall times the diameter ot the zocecia. Surface punc- 

 tulate and transversely wrinkled. The wrinkling is best 

 seen in young zocecia. The normal zocecia varv in length 

 from one and a half to three time.-; the diameter. 



Oa'Cia small; appear as small hemispherical tubercles; 

 diameter about halt that of the zocecia; j)unctulate. 



Distribution. — England : Lower Lias to Cornbrash. 

 Foreign: Sinemurian to Kimeridgian ; France and Germany. 



2. Stomatopora dichotomoides (d'Orb.). 



Alecto dichotomoidcg, d'Orbigny, 184'J, Prod. Pal. t. i. p. 288. 

 Stojiiafojjora dichntmnoides, d'tJrbigny, 18C2, Pal. Franc., Terr Cr»5t 



t. V. p. 8.34. 

 Slojitatiipora Bourhardi, Ilaimo, \H'A, Mi'-m. Soc. g^ol. Irance ser. 2 



t. V. J). 1<)4, pi. vi. lig. t). 



