104 BRITISH PALAXOZOIC FOSSILS. [Zoopuyra. 
Genus. LONSDALEIA (J/°Coy). 
Ref —M°Coy, Ann. Nat. Hist. 2nd Series, Vol. III. p. 11*. 
Gen. Char.—Corallum composed of circular, tapering, proliferous stems, not laterally united, or polygonal 
from the mutual pressure of a crowded growth ; internally composed of three areas; Ist, a cylindrical, defined, 
complex axis composed of irregular blended plates; 2nd, a cylindrical defined area of strong, vertical, radiating 
lamellze, connected by thin oblique transyerse dissepiments ; 3rd, largely cellular outer zone between the vertical 
lamellee and the external wall of the stem, composed of much curved vesicular plates extending obliquely 
upwards and outwards; outer walls of the tubes longitudinally striated and transversely rugose ; reproduction 
by circular germs developed in the cellular outer zone, and springing at once obliquely without the area of the 
parent stem, which continues its growth uninterruptedly with the slender young stem projecting from one of 
the transverse rugosities of the external surface ; the young stem seems at first only composed of the axis, and 
gradually acquires the inner lamelliferous and outer perithecal vesicular zones as it increases in size, the 
latter being widest in proportion in the adult individual. 
The little known Evismatholites Madreporites duplicatus of Martin’s ‘ Petrificata Derbiensia, may be 
looked upon as the type of this genus, which I have dedicated to Mr Lonsdale. It will he seen from 
the above notice, to unite in itself the internal structure of Strombodes (Lithostrotion Lonsd.) with the external 
characters and mode of growth of Oyathophyllum (C. dianthus, Se.) 
LonsDALEIA CRAssIcoNUS (J/°Coy). Pl. 3. B. fig. 5. 
Ref—M°Coy, Ann. Nat. Hist. 2nd Series, Vol. III. p. 12. 
Sp. Ch.—Corallum forming groups of loosely connected masses of elongate-conical stems, averaging 
six to seven lines in diameter; surface with concentric wrinkles and coarse flexuous longitudinal striz ; 
lateral branches rapidly expanding, conical, widening from their base at the rate of six lines in nine 
lines of length: horizontal section shews a central circular axis one and half lines in diameter of fine 
angulated concentric lines crossed by a few radiating ones; outside which is a circular area three lines 
in diameter, of about twenty-four vertical radiating lamellze, with few or no connecting vesicular plates 
between them except one thick circle at the circumference; the outer area composed of irregular, curved 
vesicular plates, forming large irregular cellulose texture: vertical section, the central axis of close delicate 
spirally and conically twisted lamince ; the inner area of one row of distant, delicate, irregular, curved 
transverse plates forming very open cells; outer area defined from the inner by a line on each side 
representing the bounding circle of the inner area of the horizontal section, formed of loose irregular 
cellular tissue, of large, slightly curved, vesicular plates, extending obliquely upwards and outwards, two 
in a row. 
This species is much less irregularly wrinkled than the L. duplicata (Mart. sp.), forms shorter and 
more widely turbinated masses, and is distinguished externally at a glance by the lateral branches ex- 
panding rapidly from their point of attachment to a conical form, while in the ZL. duplicata the lateral 
branches retain their original small diameter for a great length (increasing at about the rate of four lines 
in three inches), and present a strange contrast to the parent stem, as is faithfully shewn in the rough 
figure of Martin. 
* Since I published my paper above referred to, M. d’Orbigny has used the same name generically in his ‘Prodrome,’ 
(p- 25), for the Porites inordinata of Lonsdale, without however defining the Genus, and only judging of the fossiLrom the 
figure. Most of the discoveries in this work of M. d’Orbigny are dated 1847 for reasons given on p. xiii, but in accordance 
with the rules for nomenclature of the British Association for the Advancement of Science, I have supposed their true date 
to be that of their publication, which seems to be 1850, for though the title-page bears 1849 the cover bears 1850, and my 
bookseller could not obtain the work from the publisher till March, 1850. It must be delightful to M. d’Orbigny to see so 
many of his generic groups, determined in the privacy of his own study in 1847, coincide with those established by inde- 
pendent observers during the three years which succeeded previous to making his own results known. 
