NORTH AMERICAN EAJRLY TERTIARY BRYOZOA. 575 



PHYLACTELLA PARVICELLA. new species. 

 Plate 71, fig. 27. 



Description. The zoarium incrusts bryozoa. The zooecia are relatively small, 

 short, distinct, elliptical ; the frontal is convex and formed of a tremocyst with very 

 small pores separated by very minute granules. The apertura is elliptical; the 

 peristome is thin, salient, complete. 



,, . JArt=0.10mm. . f 7,3=0.40 mm. 



Measurements. Apertura i, .,_ Zooecia 7 .. __ 



Utf,=0.10 mm. Uz=0.30 mm. 



Affinities, This is the smallest of our Phylactella; it is therefore easy to de- 

 termine. Unhappily, only the figured specimen has been found, so we are ignorant 

 of the ovicell. 



Occurrence.. -Middle Jacksonian : Baldock, Barnwell County, South Carolina 

 (very rare). 



Holotype.Czt. No. 64191, U.S.N.M. 



PHYLACTELLA CRIBRATA, new species. 



Plate 96, fig. 10. 



Description. The zoarium incrusts bryozoa. The zooecia are elongated, dis- 

 tinct, ovoid ; the frontal is convex and formed of a tremocyst with numerous pores 

 in quincunx. The apertura is suborbicular, oblique, little visible exteriorly; the 

 peristome is thin, complete, salient, bearing on its proximal border a wide salient 

 mucro, placed facing the orifice of the ovicell. The ovicell is small, transverse, 

 smooth; it is hyperstomial and recumbent. A triangular avicularium somewhat 

 salient, the point directed toward the top, is placed laterally on a single extremity 

 of the transversal axis of the zooecia. 



JAa=0.16mm. . / 7,2=0.65-0.75 mm. 



Measurements. Apertura ] , ., Zooeciai, . .- ,. ... 



Ua O.lSmm. l?c=0.40-0.45mm. 



Affinities. This species is very well characterized by its sieve-like frontal of 

 tremopores, larger than ordinary, and by its lateral avicularium. 



It is to be noted that most of the known Phylactella have an aperture whose 

 diameter is close to. 0.15-0.17 mm. The genus is a perfectly natural one. 



Phylactella (Lepralia) tubiceps Eeuss, 1865, of the German Rupelian, is quite 

 close on account of the size of its tremopores and in the presence of an avicularium ; 

 it differs from it solely in the absence of a peristomie, an exterior which has given 

 the name to the European species. 



Upon examination of more numerous specimens it may be that the two species 

 will be recognized as identical. 



Occurrence. Vicksburgian ("Chimney rock" of Marianna limestone) : One mile 

 north of Monroeville, Alabama (rare). 



Holotype.Cat. No. 64310, U.S.N.M. 



