B L E N N Y. 



511 



its external appearance and other general character- 

 istics. The zinc-blende, so well known in our lead 

 mines, is called by Mohs " garnet-blende," merely 

 from its resemblance to that mineral. The yellow 

 7,inc-blende occurs along with galena or lead-glance, 

 copper-pyrites, red cobalt, and heavy-spar, in veins 

 that traverse quartz-rock, at Clifton Mine, near_Tyu- 

 drum in Perthshire; also in Flintshire. 



Very beautiful specimens are met with in Bo- 

 hemia, where it is associated with galena, grey 

 copper, iron-pyrites, brown-spar, and quartz ; and 

 sometimes also with native silver, silver-glance, or red 

 silver. It is also found at Scharfenberg in Saxony ; 

 Rammelsberg in the Hartz, in veins in transition 

 rocks. The green varieties are found at Gumerud 

 in Norway, associated with galena, and smalt-blue 

 apatite, in transition rocks; and it is accompa- 

 nied by red manganese, at Nagyag in Transylvania. 

 The foliated brown zinc-blende usually occurs mas- 

 sive and disseminated ; also in granular distinct 

 concretions, varying considerably in magnitude. It 

 is found in Scotland ; in the lead mines in England ; 

 and in various other parts of the world. 



Black zinc-blende is principally valued on account 

 of the zinc which it affords. In order to obtain that 

 metal from it, it is first roasted, to drive off the sulphur, 

 and then ground with charcoal, and exposed to heat 

 in a crucible, when the metal is reduced, and sub- 

 limes into a lute, so placed as to convey it into water, 

 where it condenses in small drops. By our English 

 miners, blende is named " black jack." 



A specimen of blende in the collection of minerals 

 at the British Museum is represented in the accom- 

 panying engraving. 



The prismatic antimony blende is a rare mineral, 

 and is considered as an ore of .silver in the districts 

 where it occurs. For an account of the rhomboidal 

 ruby blende see SILVER. 



BLENNY (Blennius}, A genus of Acanthoptery- 

 geoi/s, or spinous-fiuned fishes, belonging to Cuvier's 

 family of Gobioidce, or the gudgeons. The genus has 

 received the name blenny from the mucous matter 

 with which the skins are covered; /3Xtv being the 

 Greek for mucus. 



All the species, which are rather numerous, have 

 a very easily distinguishing character in the ventral 

 fins, which are placed before the pectorals, and have 

 only two rays in each. Their bodies are long and 

 ((impressed. They have, strictly speaking, only one 

 dorsal fin, but that is sometimes divided into two 

 lobes, which to partial observation gives it the ap- 

 pearance of two distinct and separate fins. The rays 

 of the dorsal are all entire, or without articulation, 

 but they are soft and flexible. The stomach is small, 

 and the intestine short and without any caeca. They 



are also destitute of an air bladder. Many of them 

 are viviparous, or bring forth their young alive. They 

 are found in small shoals, among rocks or near the 

 shores ; and they are very lively fishes, leaping, swim- 

 ming, and sometimes getting out of the water, where 

 they have the power of living longer than many 

 fishes, probably on account of the mucous secretion 

 with which they are covered. They are in general 

 small fishes, and of little or no use to man in an eco- 

 nomical point of view. 



Lacepede includes twenty-three species in the 

 genus, which he divides into four sections or sub- 

 genera, according to the characters of the head and 

 the dorsal fin. The first of these have two lobes in 

 the dorsal, and filamentous appendages to the head ; 

 the second have only one lobe and the filaments ; 

 the third have two lobes in the dorsal, but no ap- 

 pendages to the head ; and the fourth have one*lobe, 

 and no appendages. It does not, however, appear 

 that any particular difference of habit can be indi- 

 cated by these characters, as we are in a great mea- 

 sure ignorant of the uses of the filaments attached to 

 the heads of fishes, and also to the difference of 

 action arising from the dorsal fin being single in 

 double. Cuvier takes a different method, including 

 about eight or nine species as true blennies, and 

 ranging the others into different genera according to 

 their characters. 



The true blennies have the teeth long, closely set, 

 forming only one row in each jaw, and terminated in 

 front, in some of the species, by a recurved tooth 

 longer than the rest. They have the head obtuse, 

 the muzzle short, and the line of the forehead nearly 

 vertical. Their intestinal canal is short and wide. 

 The greater number have a fleshy or cartilaginous 

 appendage over each eye, which is divided into dif- 

 ferent branches ; and some of them have a similar 

 one on each temple. The following are some of the 

 species. 



Blennius nccllar'u, (the eye-spot olenny, or " butter- 

 fly fish"). This is a small species, seldom exceeding 

 four inches in length. It is brown with a greenish 

 tinge, and spotted. The dorsal fin is formed into 

 two lobes, the first the highest, and the first spine of 

 it the largest. It is upon this fin that the spot from 

 which it gets its name is situated. The centre of 

 the spot is a circular line of black with a purplish 

 tinge, surrounded by a circle of white, and then out- 

 side with another of the same colour as the central 

 disc. The eyes are elevated nearly to the same 

 height as the line at the top of the head ; the irides 

 of them have a silvery lustre ; and the appendages 

 over them are fringed on their posterior margins. 



This is rather a rare species in the British seas ; 

 and when it is met with it appears to be brought by 

 the current from the warm shores of Europe, as it 

 has been met with only or chiefly on the south coast 

 of England, and the shores of the Irish Channel. 

 It is, however, much more abundant in the Mediter- 

 ranean. It is always found near the shores, or other- 

 wise in shallow water among stones and marine 

 plants ; and it sometimes, in that sea, attains the 

 length of six or seven inches ; but its flesh is taste- 

 less, and it is not sought after by the fishermen. The 

 surface of its body abounds in the viscid or mucous 

 matter from which the genus is named. 



Blennius tentacularis. This species is rather longer 

 than the former. The head is compressed and blunt, 

 the eyes stand higher than the line of the crown ; 



