568 
BULLETIN 106, UNITED STATES NATIONAL MUSEUM. 
ADEONELLOPSIS GRANDIS, new species. 
Plate 99, figs. 11-18. 
Description . — The zoarium is free, bilamellar, dichotomously branched, often 
attaining more than 2 centimeters in length; the two lamellae are placed back 
to back and are separated with difficulty. The ordinary zooeeia are elongated, 
distinct, lozenge-shaped, and separated by a furrow. The peristome is almost 
complete and bears a large distal pore; the peristomie, which is rather deep, con- 
tains a small, straight avicularium, triangular on the old zooeeia and round on the 
young, and a well-hidden aperture; the peristomice is in the form of a crescent on 
the young zooeeia and rather regularly elliptical on the old ones. The ascopore is 
stellate, very small, and close to the peristomial avicularia. On the line of the 
areolae there are one or two round, simple, and little salient avicularia. ,The 
gonoecia are larger than the ordinary zooeeia ; their ascopore is replaced by a 
deep cribriform area perforated by four to six pores. 
Measurements . — Zooeeia 
X^=0.4d mm. 
lz= 0.20-0.22 mm. 
External aperture [Zooeeia = 0.06 mm. 
(width) \Gonoecia = 0.10 mm. 
„ . Zsor=0.44-0.50 mm. 
Cronoecia 7 A OA 
{lzg= 0.30 mm. 
V ariations . — The peristomial avicularium is round when it is prominent (figs. 
12, 15), but on the old zooeeia with very thick walls it becomes triangular and 
pointed; this transformation is quite remarkable, but it still does not permit one 
to discover the function of the organ itself. The ascopore is visible only on the 
young zooeeia (fig. 14). On the others it is placed in the peristomice below the 
avicularium but always quite visible. 
In thin transverse sections (fig. 16) the zooeeia are very thick. The pleu- 
rocystal elements, piled one on the other are grouped in transversal filaments. 
In tangential section, the ascopore is rarely distinct from the avicularium 
(figs. 17, 18) because they are very close to one another. 
Affinities . — This species differs from Adeonellopsis transversa in its peristomial 
avicularium, which is straight and not oblique, and in the size of the zoarium. 
The zoarial dimensions permit the species to be classified among the good-sized 
fossils useful in field determination. 
In its distal pore it resembles Adeonellopsis cyclops, but differs from it in the 
absence of the cribriform area on the ordinary zooeeia. 
Occurrence . — Vicksburgian (“Chimney rock” of Marianna limestone): One 
mile north of Monroeville, Alabama (very abundant). 
Cotypes. — Cat. No. 64319, U.S.N.M. 
ADEONELLOPSIS GALEATA, new species. 
Plate 99, figs. 1-10. 
Description . — The zoarium is free, bilamellar, erect, formed of short, dichoto- 
mously divided fronds; the two lamellae, placed back to back, are inseparable. 
