ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 631 



group of the Thaliacea, for there is but one cord, and that is solid, 

 and is composed of endodermic cells ; so far it resembles the cord 

 rather of Ascidiaa than of Thaliacea ; at the same time this character 

 is to be put against the precocious differentiation of the young bud, 

 the cells of which are derived from the endodermic cord. 



New Species of Simple Ascidians.*— M. L. Eoule describes three 

 new species of simple Ascidians from the shores of Provence, The 

 first is most like the members of the genus Molgula, but is remark- 

 able for having, as has Eugyra, only one genital gland ; the structure 

 of its gill is like that of both the genera just mentioned, so that it 

 appears to be necessary to form for it a sub-generic division of 

 Molgula, to which the name of Eugyriopsis may be applied. 



There is a new species of Microcosmos, most like M. vulgaris of 

 Heller, but differing by its larger size, the colour of its tunic, and 

 the form of its tentacles. It is called M. sdbatieri. The other 

 new Cynthiad is like Cynthia scutellata of Hiller, but is larger, has 

 its siphons approximated instead of separated, and differs by other 

 characters, among which is the fact that the genital glands are broken 

 up into small parts, each of which has its own excretory ducts ; it is 

 of a fine red colour, and is to be called Cynthia corallina. 



B. Polyzoa. 



Structure and Development of Loxosoma.j — Mr. S. F. Harmer 

 observed at Naples five species of Loxosoma, one of which, L. lepio- 

 clini, is new ; it was not uncommon on the compound Ascidian Lepto- 

 clinum maculosum. The term ventral is, in opposition to Caldwell, 

 applied to the line of the body between the mouth and anus ; the 

 dorsal region is drawn out into a stalk, on which the calyx or body 

 of the animal is carried ; when, in his descriptions, the author speaks 

 of a transverse section, he means one which passes in the plane of 

 the stalk through the right and left side ; a horizontal plane is one 

 which is at right angles to the long axis. 



In Loxosoma the buds become free as soon as they reach maturity, 

 and this genus differs therefore from all other Polyzoa in never 

 forming colonies. The cells of the ectoderm were best studied by a 

 special use of nitrate of silver ; the tissues are washed " in a solution 

 of a neutral salt (KNO3), which gives no precipitate with nitrate of 

 silver, the solution having the same specific gravity as sea-water " ; 

 there was thus no precipitate of silver chloride ; these cells were 

 found to be large and polygonal, or sense-cells, bearing one or more 

 fine, stiff^ tactile hairs which project into the water, and gland-colls ; 

 the last differ in character in different species. The foot-gland is 

 either retained by the adult or found only in the bud ; in some 

 species it has wing-like lateral outgrowtlis. It seems to be composed 

 of two distinct portions — the gland, which consists of a small number 

 of granular nucleated cells arranged round a central lumen, and a 

 " duct," which is really an open groove. 



• CoiriptcB KeiifluH, c. (1885) pp. 101.0-7. 

 t Quart. Journ. Micr. Sci., xxv. (1885) pp. 2C1-338 (3 pis.). 



2 T 2 



