Papular Bfrtt'auarn of ftntmatgtt ^attire. 239 



down when the polypus is about to advance 

 from the cell ; and, it is said, the lid of the 

 cells opens and shuts without the slightest 

 perceptible synchronous motion of the 

 polypi. Some species have cells on one side 

 of the leaves only. In the most plant-like 

 of them there is no substance in the least 



E SHA-MAT. (FTAJSTRA FOLTACEA.) 



resembling that of the plants with which 

 they agree most in form, nor is there any 

 substance similar to theirs in the most ana- 

 logous of the true vegetables ; they are often, 

 however, called " white sea-weeds." In 

 Dr. George Johnstone's admirable " History 

 of British Zoophytes," we read as follows : 

 " When recent it exhales a pleasant scent, 

 which Pallas compares to that of the orange, 

 Dr. Grant to that of violets, and which a 

 friend tells me smells to him like a mixture 

 of the odour of roses and geranium. On 

 the contrary, Mr. Patterson tells me that 

 the smell is strong, peculiar, and disagree- 

 able. It probably varies, and is often not 

 to be perceived at all." 



From the same authentic source we derive 

 the following information respecting another 

 species, Flustra membranacea ; the cells of 

 which are oblong, with a short blunt spine 

 at each comer. It is thus described : 

 "Polypidom forming a gauze-like incrus- 

 tation on the frond of the sea-weed, spread- 

 ing irregularly to the extent of several 

 square inches, in general thin and closely 

 adherent, but sometimes becoming thickish, 

 and then capable of being detached in con- 

 siderable portions ; cells very obvious to the 

 naked eye, oblong, quadrangular, with a 

 blunt hollow spine at each angle. In many 

 specimens there are some anomalous pro- 

 cesses, a quarter of an inch in height, scat- 

 tered over the surface : they arise from 

 within the cells, are simple, horny, and 

 tubular, but closed at top. When the poly- 

 pes are all protruded, they form a beautiful 

 object under the microscope, from their 

 numbers, their delicacy, the regularity of 

 their disposition, and the vivacity of their 

 motions, now expanding their tentacula 

 into a beautiful campanulate figure, now 

 contracting the circle, and ever and anon 

 retreating within the shelter of their cells. 

 The tentacula are numerous, filiform, white, 

 and in a single series. The Rev. David 

 Landsborough has seen a specimen (and I 

 have seen its equal, Dr. J. remarks) of F. 

 membranacea five feet in length by eight 



inches in breadth. " As every little cell 

 had been inhabited by a living polype, 

 by counting the cells on a square inch, I 

 calculated that this web of silvery lace had 

 l>een the work and the habitation of above 

 two millions of industrious, and, we doubt 

 not, happy inmates ; so that this single 

 colony on a submarine island was about 

 equal in number to the population of Scot- 

 land." 



FLY. A name of very general application 

 to insects furnished with wings ; but pro- 

 perly restricted to the numerous genus Musca. 

 The stroner resemblance which exists among 

 all the species of the Fly tribe, together with 

 their small size, makes it difficult to discri- 

 minate them readily ; but the general and 

 most obvious character of Flies, by which 

 they are distinguished from other winged 

 insects, is in their having transparent and 

 naked wings, totally free from the farina or 

 dust visible on those of butterflies, and in 

 having no cases or covers for them. Thus, 

 by this simple character, they are clearly 

 distinguished from the butterfly, the beetle, 

 the grasshopper, &c. The principal parts or 

 members of which Flies are composed are 

 the head, the thorax, the body, and the 

 wings ; from the number of the latter the 

 most obvious distinction for a systematic 

 arrangement of them is drawn. [See Mus- 



CIDJE.] 



FLYCATCHERS. (Mvscicapidce.) This 

 very numerous family, which receives its po- 

 pular name from the expertness of the indivi- 

 duals composing it in catching the flying in- 

 sects upon which they feed, is found widely 

 diffused throughout both the eastern and 

 western continents ; and includes many of 

 the most beautiful of the feathered tribes. 

 The general habits of the Flycatchers are 

 those of the shrikes, and, according to their 

 size, they prey on small birds or insects. 

 They have the beak horizontally depressed 

 and armed with bristles at its base, with the 

 point more or less decurved and emarginated. 

 Those which are called " Tyrant Flycatch- 

 ers" (Tyrannus) are American birds, of a 

 large size and very spirited ; they have a 

 long, straight, and very stout bill ; the ridge 

 of the upper mandible straight and blunt, 

 its point abruptly hooked : while the species 

 which inhabit Europe, and come under the 

 denomination of " Restricted Flycatchers " 

 (Mnscicapa), have shorter bristles at the gape, 

 and the bill much more slender, though still 

 depressed, with an acute edge above, and 

 the point a little curved downward. There 

 are, however, only two small species which 

 inhabit this country. 



The GREY or SPOTTED FLYCATCHER. 

 (Muscicapa ffrisoJa.) This bird is nearly 

 five inches and three quarters in length ; 

 bill broad, flattened, and wide at the base, 

 where it is beset with a few short bristles ; a 

 ridge runs along the upper mandible ; both 

 that and the under one are dusky at the tips, 

 and the latter is yellowish towards the base: 

 all the upper plumage is of a mouse colour, 

 darkest on the wings and tail ; head and 

 neck more or less obscurely spotted with 



