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Note on New or Rare British Marine Polyzoa. 



By 

 S. F. Harmer, M.A., B.Sc. 



1. Hypophordla cxpansa, Ehlers. 



IIypo2)horclla cxpansa, Ehlers, Ahh. Ges. Gbttincj., xxi., 1876, Phys. CI., 1; 



Prouho, Arch. Zool. Exp. (2), x., 1892, p. 594. 

 Dclagia chcetopteri, Joyeux-Lafl'uie, C. E. Ac. Sci., cvi., 1888, p. 620, and Arch. 



Zool. Exp. (2), vi., 1888, p. 135. 



This species was originally found by Ehlers at Spiekeroog, an island 

 off the coast of E. Friesland, in the North Sea. It has more recently 

 been found by Joyeux-Laffuie at Luc-sur-Mer (Normandy), and by 

 Prouho at Eoscoff and at Banyuls. Its wide distribution, from the 

 North Sea to the Mediterranean, made it almost certain that it would 

 be found in British waters when looked for in the right place. Ehlers 

 discovered it in the substance of the tubes of Terehella (Zanice) 

 concJiilega, while Joyeux-Laffuie and Prouho found it in the tubes 

 of Chaioptcrus. 



On one of the last days of my stay at Plymouth in April last, a few 

 Chcctopterus tubes, dredged near the Eddystone in thirty fathoms, were 

 brought to the Laboratory. Several of these tubes contained Ilypoi^lio- 

 rclla expansa, which I had no difficulty in finding by following the 

 directions given by Joyeux-Laffuie. The tube should be slit open, and 

 a thin lamella of its substance, stripped off from the inner side, should 

 be examined with the microscope. Even if the delicate zooecia are torn 

 by the operation, or if the lamella be too thin to include any zocecia, 

 the presence of the Polyzoon may be recognized by the holes through 

 which the tentacles can be protruded into the interior of the tube. 

 Each of these holes appears to the naked eye as a minute, opaque, 

 white spot. The spotted appearance of the inside of the tube is a 

 convenient indication of the presence of the Hyipopliordla, which can 

 at once be recognized by the very long, thread-like connexions between 

 the zooecia, and by the two curious vesicular cavities whicli occur, one 

 on either side of the distal end of the zooecium. Excellent figures of 



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