ZOOLOGY. 705 



sea-water. Oouirary to the view of Hancock, Nassouow thinks that the 

 spicules of the sponge take no part in the boring operation ; indeed, 

 the young sponge began before it had developed any skeletal struct- 

 ures, not to say before it had completely taken on the other characters 

 of the adult." 



With reference to the second question, it is contended that one ol* 

 the results of the parasitism of Clione is the peculiar mode of ovulation, 

 in that the sponge appears to pass its eggs into the water, where they 

 become fertilized, whereas in other sponges the eggs pass into the body 

 of the animal and are there fertilized. (Zeitschrift fur wissench. Zool., 

 vol. xxxix, pp. 295-308, 2 pi.; J. £. M. 8. (2), vol. IV., pp. 65-66.) 



A supposed new animal type. — A peculiar and unknown organism was 

 found by Prof. F. E. Schulze in the salt-water aquarium of the Zoologi- 

 cal Institute of Graz. It was a thin, lamelliform object, a few millime- 

 ters in diameter and 0.02 mm . thick, translucent, but of a grayish-white 

 color, and of a variable, constantly changing form. When at rest i t 

 had usually a rounded contour, but it could elongate itself into a long 

 and variously curling thread-like form. Its movements, however, were 

 very slow and scarcely observable, as the animal crept along upon 

 its under surface. The entire surface was ciliated. "Close under the 

 upper surface is a layer of highly refractile balls from 5* 1 to 8^ in diam- 

 eter and distributed pretty evenly; besides these there are other balls 

 nearer the under surface, which seem to be essentially different from 

 those first mentioned. There is no indication of internal organs, nor 

 of only bilateral or radiate symmetry; the organism is uniaxial." Bur 

 what is of more importance from a systematic point of view than any 

 of these details is the intimate structure. There are two different epi- 

 thelial layers of cells, which form respectively its upper and lower sur- 

 faces, and between them is a fully developed layer of connective tissue. 

 There are, in fact, three layers, which are comparable with the ecto 

 derm, mesoderm, and entoderm of Metazoans generally. Whether, how- 

 ever, the several layers of the unknown organism are really homolo- 

 gous with them may be regarded as uncertain till the development of 

 the animal is known. What the affinities of the animal are is also quite 

 doubtful. It was under observation by Professor Schulze for about a 

 year, but showed no sign of metamorphosis or reproduction. Its struct- 

 ure, exhibited in the development of the several layers, removes it from 

 the Protozoans, but this is merely negative evidence. Mr. 0. S. Minot 

 has suggested that it was the larva of a sponge, but there are objections 

 to this view. The name conferred on the organism is Triclwplax ad- 

 hwrens, the generic name containing an allusion to the plate-like form 

 and its ciliated surface, and the specific recalling the manner in which 

 it clings to the substance on which it moves. (Zool. Anzeiger, vol. vi, pp. 

 92-97; Journ. Royal Mic. Soc. (2), vol. in, pp. 350-351; Science, vol. I, p. 

 305.) 



H. Mis. 69 45 



