296 BULLETIN 100, UNITED STATES NATIONAL MUSEUM 



bears some areolar pores in the form of superficial verrucosities with- 

 out avicularia. There are numerous interzooecial avicularia. 



Genotype. — Strophiella tuberigera Jullien, 1903. Recent (Gulf of 

 Gascony). 



Genus ARTHROPOMA Levinsen, 1909 



ARTHROPOMA CECILI Savigny-Audouin, 1826 



Plate 32, fig. 1 



1889. Schizoporella cecili Jelly, a synonymic catalogue of recent marine Br\ozoa, 



p. 223. (Bibliography.) 



1890. Schizoporella cecili Ortmann, Die japanische Bryozoen Fauna, Archiv 



fur Naturgeschichte, vol. 50, p. 51, pi. 1, fig. 4. 



1890. Schizoporella cecili var. Kirkpatrick, Report on Polyzoa in China Sea, 

 Annals and Magazine Natural History, ser. 6, vol. 5, p. 22, pi. 5, fig. 8. 



1895. Schizoporella cecilii MacGillivray, Tertiary Polyzoa of Victoria, Transac- 

 tions Royal Society of Victoria, vol. 4, p. 33, pi. 11, fig. 



1907. Schizoporella cecili Calvet, Expedition scien- 

 tifique du Travailleur et du Talisman, p. 415. 

 (Complete bibliography.) 



1908. Schizoporella cecilii Robertson, Incrusting Chil- 

 ostomatous Bryozoa West Coast North Amer- 

 ica, University of California Publications, 



Fig. 126.— Arthropoma Zoology, vol. 4, No. 5, p. 288, pi. 19, fig. 43. 



cecilii Savigny-Audo- 1909. Arthropoma cecilii Levinsen, Morphological 

 uin, 1826. Two oper- Studies on the Chilostomatous Bryozoa, p. 232. 



cula of different sizes. 1910. Schizoporella cecili Thornely, Marine Polyzoa of 

 X85 the Indian Ocean, Trans. Linnean Society 



Zoology, vol. 15, p. 147. 

 1913. Arthropoma cecili Waters, Marine Fauna of British East Africa and Zan- 

 zibar, Proc. Zoological Society London, 1913, p. 508. 

 1918. Arthropoma cecili Waters, Bryozoa Cape Verde Islands, Journal Linnean 

 Society Zoology, vol. 34, p. 20. (Geographic distribution.) 



Variations. — The zooecia are often poorly oriented and arranged in 

 every direction. The intensity of calcification is extreme and a second 

 layer sometimes covers the zooecial tremocyst. The size of the oper- 

 culum is variable. 



Biology. — This species is found only on the northwest coast of 

 America but its distribution elsewhere is very great especially in the 

 northern hemisphere. However it did not reach the polar circle. It 

 is never abundant in a given locality. 

 Occurrence. — 



D. 5137. Jolo Light, Jolo; 6° 04' 25" N.; 120° 58' 30" E.;20 



fathoms; S. Sh. 

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



27' 15" E.; 24 fathoms; co. S., Sh.; 17.2° C. 

 D. 5217. Anima Sola Island, between Burias and Luzon; 13° 20' 

 N.; 123° 14' 15" E.; 105 fathoms; crs. gy. S. 



