URXATELLA GRACILIS, A FRESII-WATER POLYZOAN. 
15 
Polyps exceecliiiglj' sensitive, on the slightest disturbance closing their hell and lK)wing the 
highlj^ flexible muscular steins, which often become more or less revolute. The species nearly 
resembles P. gracilis, and may be the same. It has no median dilatation to the stem, and this is 
long and slender, and even becomes revolute when the animal is disturbed, while in P. gracilis it 
appears simply to bend downward from the base. 
BARENTSIA. 
Barentsia bulbosa. 
Hincks : An. Nat. Hist., 1880, 285, PI. XV, figs. 12-14. Urban : Ibidem, 27C. 
Locality. — Barent’s Sea. 
URNATELLA. 
Urnatella gracilis. 
Leidy : Proc. Ac. Nat. Sc., 1851, 321 ; 1854, 191 ; 1858, 1 ; 1810, 100. Allman : Fresh-water 
Polyzoa, 1856, 117. 
! Urnahella “ d’eau douce de PAustralie.” Salensky : An. Sc. Nat., 1877, 47. 
Locality. — Scliuylkill River, Philadelphia ; Scioto River, Ohio. 
LOXOSOMA. 
Keferstein, 1863. 
Strephenterus, 1861. Norman. Described by the author as an echinoderm, but as he subsc- 
quentlj" (recognizing the true position of the animal on which the genus was founded), adopted 
the later name, with other authors, I have followed him. 
1. Loxosoma singularb. 
Keferstein : Zeits. was. ZooL, 1863, 131, Taf. XI, fig. 20. Claparede : Beob. u. Anat. u. Entw. 
wirb. Thiere Normandie, 1863, 105, Taf. II, figs. 6-10. Schmidt : Arch. mikr. Anat., 1876, 3. 
Barrois : Embryol. d. Bryoz., 1877, 9, 10, PI. I, XVI, fig. 6. Hincks : British Marine Polyzoa, 
1880, 573, PI. 81, fig. 78. Norman: An. Nat. Hist., 1879, 137. Urban: Ibid., 1880,270. 
Locality. — St. Vaast-la-PIogue, Normandy ; Shetland Islands; Barent’s Sea. 
2. Loxosoma neopolitanum. 
Kowalewsky : Mem. Acad. Sciences, St. Petersbourg, 1866. Norman : An. Nat. Hist., 1879, 137. 
Locality. — Bay of Naples. 
3. Loxosoma kefersteinii. 
Claparede : An. Sc. Nat., 1867, 28, PI. VI, figs. 1-3 ; Zeits. f. wis. Zook, 1870, 34, Taf. XI, fig. 4. 
Nitsche: Ibid., 1875, 451; Supplem., 361, Taf. XXV, figs. 4-20, Taf. XXVI, figs. 7-13. 
Norman : An. Nat. Hist., 1879, 137. 
Locality. — Bay of Naples. 
4. Loxosoma claviger. 
Strephenterus claviger. Norman : An. Nat. Hist., 1861, 112, PI. IX, figs. 1-4. 
Loxosoma phascolosomatum. Vogt: Arch. Zool. Exp., 1876, 305, PI. XI, XII. Barrois; 
Embiyol. Bryozoaires, 1877, 8, PI. XVI, figs. 3, 4. Norman: An. Nat. Hist., 1879, 133, 
137. Hincks: British Marine Polyzoa, 1880, 574. 
Locality. — Roscoff; Bantry Bay, Ireland. 
5. Loxosoma cochlear. 
Schmidt: Arch. mikr. Anat., 1876, 3 ; Zeits. f. wis. Zool., 1878, 69. Norman: An. Nat. Hist., 
1879, 137. 
Barrois views it as the same with L. neapolitanum. 
Locality. — Bay of Naples. 
