86 BULLETIN 81; UNITED STATES NATIONAL MUSEUM. 



Genus PLCESOMA Herrick. 



PlcBsoma Herrick, Bull. Denison Univ., vol. 1, 1885, p. 57 .=Gomphogaster Vorce, 

 Proc. Amer. Soc. Micr., vol. 9, 1888, p. 250. 

 Type (monotype). — Plcesoma lenticulare Herrick. 



PLCESOMA HUDSONI (Imhof). 



Gastropus hudsoni Imhof, Zool. Anz., vol. 14, 1891, p. 37. 



Gastroschiza flexilis J AGERSKiOLD, Zool. Anz., vol. 15, 1892, p. 448. 



Bipalpus vesiculosus Wierzejski and Zacharias, Zeitschr. Wiss. Zool., vol. 56, 1893, 

 p. 236, pi. 13, figs. 1-5. Type (by present designation) of genus Bipalpus Wier- 

 zejski and Zacharias, 1893. 



Dictyoderma hypopus Lauterborn, Zool. Jahrb., Abt. Syst., vol. 7, 1893, p. 268, 

 pi. 11, figs. 1, 2. Type (monotype) of genus Dictyoderma Lauterborn, 1893. 



Plcesoma Tiwdsom Jennings, Zool. Anz., vol. 17, 1894, p. 56. 



Plcesoma sibirica Daday, Dritte Asiat. Forschungsr. Graf. Zichy, vol. 2, 1901, p. 453, 

 pi. 24, figs. 1-4. 



PLCESOMA LENTICULARE (Herrick). 



Plcesoma lenticulare Herrick, Bull. Denison Univ., vol. 1, 1885, p. 57, fig. 3 (on page 



preceding index). 

 Gomphogaster areolatus Vorce, Proc. Amer. Soc. Micr., vol. 9, 1888, p. 250, figs. 1-G. 



Type (monotype) of genus Gomphogaster Vorce, 1888. 

 Gastropus ehrenbergii Imhof, Zool. Anz., vol. 14, 1891, p. 37. 

 Gastroschiza foveolata Jagerskiold, Zool. Anz., vol. 15, 1892, p. 447, figs. 1, 2. 

 Bipalpus lyncev^ Wierzejski and Zacharias, Zeitschr. Wiss. Zool., vol. 56, 1893, 



p. 240, pi. 13, figs. 6-10. 

 Plcesoma lynceus Jennings, Zool. Anz., vol. 17, 1894, p. 55. 



PLCESOMA TRLACANTHUM (Bergendal). 



Gastroschiza triacantha Bergendal, Acta Univ. Lundensis, vol. 28, 1892, sect. 2, No. 



5, p. 1. Type (by present designation) of genus Gastroschiza Bergendal, 1892. 

 Bipalpus triacanthus Bilfinger, Jahresh. Naturk. Wiirttemberg, vol. 50, 1894, p. 54, 



pi. 3, figs. 13-18. 

 Plcesoma triacanthum Jennings, Zool. Anz., vol. 17, 1894, p. 56. 



PLCESOMA TRUNCATUM (Levander). 



Gastroschiza truncata Levander, Acta Soc. Fauna Flora Fennica, vol. 12, No. 3, 1894, 



p. 25, pi. 1, figs. 9-10. 

 Plcesoma truncatum Weber, Rev. Suisse Zool., vol. 5, 1898, pp. 740, 743, pi. 24, figs. 



8-10. 

 Gastroschiza truncata triangulata Zernov, Izv. Imp. Obshch. Lfub. lEstestv., vol. 98, 



1901, p. 31, pi. 4, fig. 26. 



Doubtful or insufficiently described species: 



Plcesoma lynceum (Ehrenberg). 



Salpina lynceus Ehrenberg, Abh. Akad. Wiss. Berlin (for 1833), 1834, p. 219. 



Euchlanis lynceus Ehrenberg, Infusionsth., 1838, p. 464, pi. 58, fig. 3. 



Gastroschiza lynceus Bergendal, Acta Univ. Lundensis, vol. 28, 1892, sect. 2, 

 No. 5, p. 2. 



Plcesoma lyceum Weber, Rev. Suisse Zool., vol. 5, 1898, p. 737. 

 Ploesoma molle (Kellicott). 



Plcesoma mollis Kellicott, Proc. Amer. Soc. Micr., vol. 19, 1897, p. 47. 



Ploesoma molle Weber, Rev. Suisse Zool., vol. 5, 1898, p. 741. 



