80 PEOCEEDIlirGS OF THE NATIOIirAIi MUSEUM VOI..72 



Our living specimens were in reproduction January 30 and March 

 19, 1885. Up to the present the species has been dredged only from 

 depths of water below 42 meters. 



Occurrence. — Albatross Station D. 2362, east of Yucatan; 22° 08* 

 30'' N.; 86° 53' 30" W.; 25 fms.; coral sand. 

 Albatross Station D. 2363, east of Yucatan; 22° 07' 



30" N.; 87° 06' 00" W.; 21 fms.; coral. 

 Albatross Station D. 2414, Gulf of Mexico; 25° 04' 

 30" N.; 82° 59' 15" W.; 26 fms.; fine white sand, 

 broken shells. 

 Florida, 14-30 meters (Smitt) ; Tortugas, 16-29 meters 



(Osburn) . 

 Albatross Station D. 2405. 



Pliocene: Minnitimmi Creek, Bocas Island, Almirante 

 Bay, Panama. 

 Plesiotypes.— Cat. No. 7568, U.S.N. M. 



PETRALIELLA BISINUATA GRANDIS, new variety 



Plate 33, Figures 5, 6 



In this new variety the aperture is larger and measures 0.30 mm. 

 in width (and not 0.20 mm.). The avicularia are larger and measure 

 0.15 mm. in length instead of 0.12 mm. The inferior face shows the 

 same small radicular pores which we have observed on the typical 

 specimens. 



Occurrence. — Pliocene : Minnitimmi Creek, Bocas Island, Almirante 

 Bay, Panama. 



Eolotype.— Cat. No. 70851, U.S.N.M. 



PETRALIELLA MARGINATA, new species 



Plate 16, Figures 6-11; text Figure 12i 



Description. — The zoarium is free, unilamellar, formed of more or 

 less expanded fronds. The zooecia are distinct, separated by a sal- 

 ient thread, large, elongated, rectangular ; the shield is incomplete and 

 is not developed above the aperture; it is broad inferiorily and bears 

 laterally two small avicularia; the frontal is flat, perforated by large 

 tremopores, often coalescent, and ornamented laterally with short 

 interareolar costules. The aperture is semicircular, somewhat elon- 

 gated or a little transverse; two very short cardelles, placed very 

 low, separate a very large anter from a very small poster; the proxi- 

 mal border is straight and finely serrate. The ovicell is very large, 

 globular, with minute perforations ; it is hyperstomial, buried in the 

 distal zooecium closed by the operculum and bordered by a thin 

 thread. The large avicularium is placed laterally in the neighbor- 

 hood of the aperture below a small apertural avicularium; it is oblique, 

 triangular, very elongated, with unguiculate beak and provided with 

 a pivot. The inner face of the zoarium bears distally on each zooe- 



