760 SUMMAKY OF CURRENT RESEARCHES RELATING TO 



form • in the Acantharia we have the quadrate octohedron, where 

 twenty radial spines are arranged in five sets of four spines each, 

 which are set quite regularly in meridional planes. In the Nassellaria 

 or Monopyleas there is at first a monaxial form, which is in many 

 cases rendered bilaterally symmetrical; this is true also of the 

 Phgedoria or Tripyleso. Stereoscopic forms are seen in the Spumel- 

 laria. 



The Sphferoida, which may be regarded as the stem-form of all 

 Eadiolaria, ordinarily retain the spherical form of the central capsule, 

 and frequently give rise to the endosphseric polyhedron ; from these, 

 more complex forms arise by the development of spines along certain 

 rays. The Prunoidea are at first monaxial ellipsoids, and they finally 

 produce the much more complex Zygartidae. The Discoidea arise 

 from the Sphaeroida by the shortening of the vertical primary axis, 

 and they at first have the form of biconvex lenses. The Larcoidea 

 begin with simple ellipsoid shells, and become complicated by the 

 development of further systems of network. 



Polythalamian from a Saline Pond.* — E. v. Daday describes 

 a new genus — Entzia — of Polythalamians from saline waters, which 

 have been studied by Prof. Entz, who finds that the infusoria living 

 therein are new forms, or have as yet been found in the sea only, or 

 are common to both fresh and sea water, while a fourth of the whole 

 number are only known as fresh-water forms. The new genus is 

 characterized by having a multicamerate imperforate shell, which 

 contains a large number of siliceous plates ; the chambers are coiled 

 from left to right, and are only completely visible from the convex 

 side ; at the outer partition of the terminal chamber there are ^ j,rger 

 orifices, which are oval and tubular, and two smaller which are .ircular. 

 Tetrastomella is proposed as the specific name. 



In the form of its shell Entzia resembles Botalia, and belongs 

 to the group of the Helicostegia ; the largest of the 16-chambered 

 individuals measured 0*42 mm., while the smallest 6-chambered 

 shell measured only 0*08 mm. As in Botalia, the partitions 

 between the chambers were formed of two lamellse, one belonging 

 to the chamber in front and the other to that behind, but there 

 is not here any interseptal space ; in all, as in the last partition, 

 there are two large and two smaller holes. As the siliceous 

 plates are completely imbedded in the substance of the shell, 

 the surface of the latter is, notwithstanding their presence, quite 

 smooth ; they cannot, therefore, be regarded as foreign bodies, but 

 must be supposed to have been formed by the protoplasm. On the 

 whole, an investigation into the characters of the shell shows that it 

 unites peculiarities which are separately characteristic of chitinous 

 and arenaceous Ehizopods, and the close allies of the form are to be 

 found not so much in Botalia, which it resembles in appearance, as 

 in Difflugia and the arenaceous Mono- and Polythalamia. The author 

 sums up his views as to the systematic position of Entzia in the 



* Zeitschr. f. Wiss. Zool., xl. (1884) pp. 465-80 (1 pi.). Cf. Grubev's note, 

 this Journal, ante, p. 580, which should have followed tlie above. 



