518 BULLETIN 100, UNITED STATES NATIONAL MUSEUM 



Order CYCLOSTOMATA Busk 

 Division INOVICELLATA 



Family DIASTOPORIDAE Gregory, 1899 



Forma PROBOSCINA Audouin, 1826 



PROBOSCINA DICHOTOMA D'Orbigny, 1839 



Plate 76, figs. 1, 2 



1837. Criserpia dichotoma D'Orbigny, Voyage dans l'Amerique Meridionale, 

 vol. 5, pt. 4, p. 19, pi. 9, figs. 7-13. 



1904. Stomatopora dichotoma Waters, Resultats Voyage Belgica, Zoologie, p. 87. 



1905. Stomatopora dichotoma Waters, Recent Bryozoain D'Orbigny's Collection, 



Annals Magazine Natural History, ser. 7, vol. 15, p. 14. 



Measurements. — Diameter of peristome, 0.16 mm.; distance of 

 orifices, 0.56; and width of branches, 0.36. 



Our photograph resembles D'Orbigny's figure very much. The 

 diameter of the aperture indicated as 0.14 mm. by Waters, measured 

 0.12 mm. on our specimen for the peristome is thick. 



Specific determinations can not be rigorously exact in this genus 

 and it is necessary, the greater part of the time, to be content with 

 simple approximation. 



We have found in the Philippine Archipelago, as well as in the China 

 Sea, various specimens of Proboscina and of Stomatopora but we did 

 not think it advisable to publish them as species on account of the 

 inexact relation between such examples. 



Occurrence. — 

 D. 5151. Sirun Island, Sulu Archipelago; 5° 24' 40" N.; 120° 



27' 15" E.; 24 fathoms; co. S., Sh. 

 D. 5311. China Sea, vicinity of Hong Kong, 21° 33' N.; 116° 

 15' E.; 88 fathoms; crs. S., Sh. 



Geographic distribution. — Malouines Islands, Cape Horn (D'- 

 Orbigny). Antartic; 70° 23' S.; 82° 47' W. long; 80 meters; 0.8° 

 C. (Waters). 



Plesiotype — Cat. No. 8326, U.S.N.M. 



PROBOSCINA COAPTA, new species 



Plate 76, fig. 10 



Description. — The zoarium encrusts shells; it is formed of wide 

 branches ramified at a large angle and containing 5 to 6 longitudinal 

 rows of tubes. The tubes are distinct, convex, separated by a deep 

 furrow, short; the orifices are subelliptical and arranged in oblique 

 or transverse rows. 



Measurements. — Diameter of peristome, 0.12 mm.; diameter of 

 tubes, 0.16; distance of tubes, 0.34; and width of branches, 0.70. 



