1239 



ZURLITE. 



ZYQOPHYLLACE.E. 



1290 



and united after the manner of a crest; anterior feet tubercular 

 externally; the succeeding feet hollowed with furrows on their 

 external surface. Length from about 2 to 3 inches : colour yellowish 

 with reddish spots. It is found in the Indian Ocean. 



cylindrical, and are four times as long as broad : the colouring matter 

 ia arranged in a triple irregular series of dots. This species is not so 

 common as the others. When young it is of a dull pale green colour, 

 and only three imperfectly spiral lines of globules ara distinguishable, 



Zozymus ttneus. 



ZURLITE, a Mineral occurring crystallised and massive. Primary 

 form a cube or square prism. Cleavage indistinct. Colour asparagus- 

 green, inclining to gray. Fracture conchoidal. Hardness about 6'0. 

 Lustre resinous. Opaque. Specific gravity 3'27. Found on Vesuvius. 



ZUIINAPA, the Arabian name, according to Belon, of the Giraffe. 



[GlRAFFA.] 



ZUZARA. [ISOPODA.] 



ZYQyENA. [SQUALID.*:.] 



ZYQMJUIDJE, a tribe of Insects belonging to the order Lepidoptera, 

 placed by Linnaeus with the Sphinges on account of the resemblance 

 of their antennae to those of that family. Latreille divided them into 

 two groups, according to the forms of the antennae, which in the one 

 are simple or scarcely pectinated, but are entirely so in tbe other, at 

 least in the males. Seiia and Zyyana are examples of the former; 

 J'rocrii and Aylaope, of the latter. 



The genus Zygcena includes some very beautiful insects, which, 

 while they resemble moths in general aspect, fly during the day and 

 in full sunshine. When at rest they deflex their wings. Their cater- 

 pillars have six feet, are pilose, and are not furnished with the corne- 

 ous tubercle which those of the Sphinges bear on the last rin; of the 

 body. Unlike the last-named insects, they do not bury in the ground 

 to undergo their metamorphosis, but spin a spindle-shaped cocoon of 

 silky texture, which they attach to the stems and branches of grasses. 



Zygcena filipendula, a greenish-black insect with six crimson spots 

 on its upper wings, and red under-wiugs bordered with black, is a 

 common British species. 



ZYGNE'MA (from {tyor, a yoke, and vrt^a, a thread), a genus of 

 Plants belonging to the family Confenacea?, of the natural order Algae. 

 This genus is characterised in Hooker's ' British Flora ' by the follow- 

 ing structure: The filaments simple, finally united by transverse 

 tubes ; the endochrome forming dotted spiral rings, which, after con- 

 jugation, are condensed into a globule in one of the filaments. Four 

 species of this genus are described as British by Dr. Harvey, in the 

 fifth volume of Smith's ' English Flora.' These nre as follow : 



Z. nitidum, with dark-green filaments, parallely joined, and the 

 articulations with numerous arching spines. This is a very common 

 species, and is found abundantly in our fresh-water ditches. "After 

 conjugation," Mr. Harvey observes, "the filaments become crisped, 

 fragile, and lose much of their lubricity ; the spires are soon after 

 decayed, and the contents of one urticulation discharged through its 

 tube into the opposite one, where they form a dark-coloured globule. 

 The other species undergo similar changes." 



Z. deciminum, with dark-green filaments joined, in a parallel 

 way, the spires doubly cruciate. This is also an extremely com- 

 mon species. Its joints are very variable in length. The granules, 

 arranged in a spiral form, cross each other, so as to give them the 

 appearance of the continued multiplication of the Roman numeral X, 

 whence the specific name. 



Z. quinium has pale yellow-green filaments, which are parallely 

 joined with simple spires. This is also a common species. The 

 spiral lines in this species resemble the multiplication of the Roman 

 numeral V. 



Z. curvatum has green unbranched filaments, very slender, and here 

 and there alightly bent, and combined by their angles ; the joints are 



These lines become afterwards more conspicuous, the rest of the fila- 

 ments being nearly colourless, and their component granules larger 

 The threads or filaments unite here and there, but not at every joint, 

 and the processes which connect the filaments together are not situated 

 in the middle between the two joints. In some of the combined 

 joints the contents appear unchanged, and in others they form a mass 

 of larger granules than in the lines, and some have a large oval seed, 

 which often swells the joints. 



ZYGODA'CTYLI, the term used by M. Temminck, M. Vieillot, and 

 others, to designate those perching birds which have their feet com- 

 posed of two anterior and two posterior toes, the external toe of the 

 two last mentioned being capable of a direction either forward or 

 backward. The Parrots, Woodpeckers, Toucans, Cuckoos, &c., belong 

 to this group, which forms the first tribe of the second order (Sylvicolce) 

 of M. Vieillot, and the fifth order of M. Temminck. 



ZYGOPHYLLA'CEJE, Sean Capers, a natural order of Exogenous 

 Plants. Seven genera are referred to tl.is order, and the number of 



Tribultts cistoidei. 



1, cutting, with leaves and flowers; 2, flower separated; 3, pistil deprived 

 of calyx and corolla, showing the disc and glands ; 4, section of fruit. 



