DINOPHILUS GARDINERI (S/>. AW.). 

 ANNE MOORE. 



PRELIMINARY NOTE. 



A NEW species of Dinophilus was found in the summer of 

 1897, by Dr. E. G. Gardiner, at Woods Roll. The pool in 

 which it is found is an artificial one, 12 by 14 feet, dug about 

 eight years ago to obtain the peat in the marsh. Sea water 

 does not flow into it, but when the tide is unusually high it perco- 

 lates in through the sand. The salinity of the water is there- 

 fore subject to great variation, for a run of low tides results in 

 condensation through evaporation, while heavy rains dilute it. 

 In May, 1898 and 1899, DinopJdlus was found by Dr. Gardiner 

 in abundance upon green algae floating on the surface of the 

 water. In June, 1898, he kindly brought the animal to my 

 notice and I began 'work upon it. At that time it was not 

 abundant, and by July 16 had entirely disappeared. In 1899 

 only two specimens were seen after June 28. Both years the 

 disappearance was coincident with a rainstorm, so that it is quite 

 possible that the influx of fresh water may account for it. Other 

 observers (Hallez, 1 Weldon, 2 Harmer 3 ) have noted the period- 

 ical disappearance of Dinophilus. Weldon attributes it to the 

 disintegration of the female, consequent upon the setting free 

 of the ova, but Schimkewitsch 4 maintains that eggs may be 

 laid several times during the year, and that the female lives 

 for some time after depositing them. He found special ducts 

 present for carrying the eggs to the exterior, so that there 



1 Hallez, P., Contributions a r Histoire Naturelle dcs Tnrbellairt:s. Lille, 1879, 

 p. 155. (D. metameroides.) 



2 Weldon, W. F. R., " On Dinophilus gigas," Quart. Joitrn. Micr. Sci. Vol. 

 xxvii. 1887. 



3 Harmer, S. F., " Notes on the Anatomy of Dinophilus," p. 109, Jouni. Jlfur. 

 Biol. Ass. of United Kingdoms. New Series. Vol. ii, October, 1899. 



4 Schimkewitsch, W., " Zur Kenntnis des Baues und der Entwicklung des 

 Dinophilus vom Wei Ben Meere," Zcit. fiir wiss. Zool. Bel. lix. 1895. 



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