GENUS LAGYNIS. 65 



it projects in advance, those which it leaves behind it (so to speak) being retracted into the 

 general mass of the body, from which new ones are put forth in front. 



Genus III.— Lagynis (Plate I, fig. 21). 



79. It may be doubted whether this genus, first discovered by Prof. Schultze 

 (.xcvii, p. 56) in the Baltic sea in the year 1849, should be ranked as an aberrant type of 

 the family Gromida, or should be removed to the Adinoplirijan group ; the intermediate 

 character of its pseudopodian extensions, and the strong resemblance of its " test " to that of 

 JSurjlyjjha, being such as to justify either position. This " test," which seldom exceeds 1 -240th 

 of an inch in length, is unattached, membranous, transparent, and elastic, and has somewhat 

 the form of a retort with a prolonged neck and a large aperture. The sarcode-body rarely 

 fills its cavity, the posterior part of which is generally unoccupied save by four tapering pro- 

 longations, that come off from the hinder part of the sarcode-mass which occupies the central 

 part of the cavity, and extend themselves backwards so as nearly to meet each other at the 

 posterior extremity of the "test" (Plate I, fig. 21, .\). These processes, with the part of 

 the sarcode-body from which they proceed, are composed of a granular sarcode more 

 opaque than the rest; and this is disposed, in the middle portion of the cavity of the test, 

 around a bright globular centre. The anterior portion of the cavity, on the other hand, is 

 occupied by sarcode of peculiarly pellucid character ; and it is this which extends itself into 

 the pscudopodia that issue from the orifice. These pseudopodia, like those of the HHiculuria 

 generally, are very slender, in this respect contrasting very strongly with those of the typical 

 Ammham (though not unlike those of A. porrecta, fig. 18), but more resembling those of 

 certain Actinopliryans. They diverge and occasionally subdivide ; but do not extend to more 

 than two or three times the length of the shell; and they show little or no tendency to 

 reunite (as in Gromia), so as either to form a network or to establish fresh centres of ramifi- 

 cation. The sarcode-substance has not been seen to extend itself (as in Gromia) backwards 

 from the orifice over the surface of the test, so as to give off pseudopodia laterally and 

 posteriorly. Occasionally the sarcode-body is found to occupy only the posterior part of the 

 cavity of the test, and to present the form of a sphere without any prolongations, its bright 

 pellucid centre being still distinguishable in the midst of the darker substance (fig. 21, b). 

 Whether this retracted condition has any relation to the " encysted " state of Infusoria, is a 

 point still to be determined. It is pointed out by Prof. Sehultze that the " test " of 

 Lru/yiits hears a close resemblance to one described by Perty (lxxxii, Plate viii, fig. 21), 

 under the name of Eiyhipha currala, as having been found empty on the Simplon, at a height 

 of from 4000 to 5000 feet. 



