62 BULLETIN 16 5, UNITED STATES NATIONAL MUSEUM 



subcircular ; the secondary aperture is subcircular; there are four 

 spines, somewhat thickened. 



The ancestrula, about 0.36 mm long and 0.18 mm wide, is elliptical ; 

 the gymnocyst is of small extent and not hidden by secondary tissue 

 (epicalcification) ; the frontal is well arched, consisting of about 12 

 costae, each with about 3 pelmatidia and 3 pairs of wide costal fu- 

 sions which leave but very small perforations (lacunae) between the 

 costae ; the costae are firmly united in a median band of fusion ; the 

 apertural bar is much raised in the neighborhood of a pair of pelma- 

 tidia; the apertura is subcircular, flattened proximally; there are 

 five apertural spines. 



Remarks. — The presence of five apertural spines in the ancestrula 

 of Hesperopora occidentalis 13 is of interest in showing that the four 

 apertural spines are a reduction of a larger ancestral number. H. 

 occidentalis is more primitive in many characters than H. danica, 

 and it may be considered as ancestral to that form. 14 



Occurrence. — Vincentown limesand: Near Blackwoodstown, N.J. 

 (very rare). 



Plesiotype.—U.S.tlM. No. 73921. 



Genus STICHOCADOS Marsson, 1887 



STICHOCADOS COMPOSITUS Lang, 1916 



Figure 1, A ; Plate 13, Figures 6, 7 



1916. Stichocados compositus Lang, Ann. Mag. Nat. Hist., ser. 8, vol. 18, p. 98. 

 1922. Stichocados compositus Lang, Catalogue of the Cretaceous Bryozoa in the 

 British Museum, vol. 4, pt. 2, p. 178, text fig. 57, pi. 4, fig. 3. 



Diagnosis. — " Stichocados with about 9 costae ; 3 or 4 lateral costal 



fusions (?); length 0.5 mm; a pair of small apertural avicularia." 



Description. 15 — The zoarium is free, unilamellar in small masses of 



2 to 3 mm in diameter. The zooecia, about 0.5 mm long and 0.4 mm 

 wide, are oval, bottle-shaped, erect; the mural rim is of very small 

 extent; little or no interzooecial calcification; the frontal is well 

 arched, consisting of about 9 costae, each with 3 or 4 pelmatidia and 



3 or 4 pairs of lateral costal fusions 16 united in a median band of 

 fusion; the apertural bar is probably formed as in the last species, 

 that is, with a median projection that fuses with lateral structures, 

 but in this case a pair of apertural avicularia replaces the proximal 

 pair of apertural spines to form a fenestrated proximal shield of a 



13 We have not rediscovered good specimens of this species in our collections and are 

 giving Lang's text, but in our usual terminology. 



14 On the figures given by Lang we cannot see distinctly the two apertures of which he 

 speaks. 



16 A combination of Lang's text with our own notes. 



16 The lateral costal fusions are the trabeculae separating the lacunae. 



