472 SUMMARY OF CURRENT RESEARCHES RELATING TO 



of nutrition, and on the dependence of their organization on external 

 conditions. With regard to this last, it is pointed out that the Imper- 

 forata grow smaller at greater depths ; as to the Perforata, the same 

 is partially true, but late investigations show that temperature has no 

 inconsiderable influence. The composition of the water has an influ- 

 ence on the characters of the shells. In the discussion on Bathybius, 

 Haeckel's opinion that Bathybius is only found locally and is confined 

 to the northern seas, is quoted. It is believed that Bessel's account 

 is worthy of all confidence ; but it is pointed out that in the original 

 Bathybius-slime Giimbel found only 3 • 05 per cent, of organic matter, 

 and no sulphuric acid at all. 



The Khizopoda are divided into the sub-orders (1) Amoebeaa 

 and ( 2) Testacea ; and an account is given of Eozoon (the verdict on 

 which is left to the reader, though the author inclines to the view 

 of its being inorganic) and of the Stromatoporida. 



Acineta dibdalteria, a New Species of Marine Infusorian from 

 the Gulf of Genoa.* — Dr. C. Parona describes a new Acineta, of 

 peculiar characters, especially in regard to the suckers, which are not 

 borne by a trunk, and are not ramified. It is solitary and attached 

 by means of a slender peduncle to various marine Alg«, and is toler- 

 ably abundant. The suckers were found to be very remarkable. 

 Instead of being collected into bundles and arranged symmetrically 

 on one side and the other of the body, or distributed over the whole 

 of the free surface of the protoplasm corresponding to the aperture of 

 the test, they are only two in number, placed opposite one another. 

 Whilst in the other Acinetce these sucking tentacles are slender, more 

 or less long, and usually rigid; in the new species they are flexible* in 

 all directions, and very mobile, so that they move and twist about 

 continually. 



The author has not met with these characters in any other Acineta 

 hitherto described, and therefore proposes to establish, if not a new 

 genus (so as not to complicate further the divisions of the group), at 

 least a new species, under the name of 



Acineta dibdalteria sp. nov. — Diagnosis : — Test in the form of 



a wine-glass ; peduncle slender ; tentacles single ; protoplasm 



granular, more transparent at the periphery ; contractile vesicle 



large ; nucleus in the shape of a horseshoe, and placed towards the 



lower part of the protoplasmic mass. Only two tentacles, which are 



at the same time suctorial and prehensile, movable in all directions ; 



peduncle straight, slender, of uniform diameter, and only a little 



widened towards the base to attach itself more firmly to the plant 



which bears it. 



Dimensions. .,, 



Mm. 



Transverse diameter of the test (maximum) . . . . 0'06 



Vertical diameter of the test 0*05 



Length of the peduncle 0"03 



Breadth of the peduncle 0"01 



Length of the suckers 0*04 



* Arch. Sci. Phys. at Nat. (1881) p. 181. See Anu. and Mag. Kat. Hist., 

 vii. (1881) pp. 279-80. 



