STARFISHES 



STARLING 



687 



Fig 6. Pluteus larva 

 with young Ophiu- 

 roid developing within 

 it. 



With few exceptions (e.g. Amphiura squamata), 

 the brittle-stars are unisexual. In most the eggs 

 are liberated as such, are fertilised externally, and 

 develop in the water ; but some species e.g. 

 Ophiopholis bellis, Ophiocoma vivipara produce 

 their young alive (viviparously), and in these cases 

 the genital clefts are enlarged to form distinct 

 brood-chambers. The openings of the clefts admit 

 water, and thus aid in respiration. When the 

 young are born viviparously 

 they are more or less like 

 the parent Ophiuroid, and 

 have no free-swimming lar- 

 val stage, but where the 

 eggs develop freely in the 

 water, the result is a strange 

 swimming larval form utterly 

 unlike a brittle-star. This 

 so-called ' Pluteus ' is fanci- 

 fully compared to a many- 

 legged painter's easel, the 

 legs being rods of lime which 

 project from the body of 

 the larva. Similar forms are 

 characteristic of sea-urchins 

 (Echinoids). As in other 

 Echinoderms, the develop- 

 ment is indirect. It is well 

 known that in the panic of capture the brittle-stars 

 justify their name by giving off their arms with 

 singular facility. .This pathological process is 

 doubtless advantageous, for, like other Echino- 

 derms, the brittle-stars have great powers of 

 regeneration. They can grow new arms or new 

 points, and thus recuperate their injuries ; and 

 in some species of Linckia and Ophidiaster an 

 isolated arm may produce other arms. 



The brittle-stars are world-wide in their distribu- 

 tion, or occur at least in all seas yet dredged. The 

 depth of their habitat varies greatly. ' More than 

 two hundred species are restricted in their range 

 to a zone of thirty fathoms,' but ' sixty -nine species 

 descend below one thousand fathoms, and about 

 eighteen below two thousand.' About fifty fossil 

 species are known. Some are said to appear in 

 tne Silurian and Devonian, but about these very 

 ancient forms not much is certainly known. In 

 the higher Mesozoic strata, however, they become 

 frequent, and are especially numerous in Jurassic 

 beds. 



The Ophinroids form the most numerous class 

 of Echinodermata, and may be divided into two 

 distinct orders (a) the Ophiurida, with unforked 

 arms, which cannot be rolled up towards the 

 mouth, and usually have distinct limy shields ; (b) 

 Enryalida, often with forked arms, which can be 

 rolled up towards the mouth, and have not distinct 

 limy shields. 



Important Forms. (1) Ophiurida. -Among the 

 commonest British species are the Common Sand- 

 star (Ophiura texturata), the Lesser Sand-star (0. 

 albida), and the Common Brittle-star (Ophiocoma 

 rosula). In North- European seas Ophioglypha 

 tacertoia is very common. Ophiopholis bellis is 

 viviparous. Ophiactis virens divides spontaneously. 

 The very widely distributed Amphiura squamata 

 is hermaphrodite, viviparous, and phosphorescent. 

 Ophiopsila aranea is another luminous form. Ophi- 

 othrix fragilis is one of the most abundant species, 

 and Ophiothrix echinata is common on Mediter- 

 ranean shorea Ophiomyxa leads on to the Enryalida, 

 which in its soft skin and general appearance it 

 markedly resembles. (2) Enryalida. The very 

 curious Gorgonocephalus or medusa-headed brittle- 

 star is one of the best-known genera in this 

 division. The anus are repeatedly forked, and as 

 they curl in towards t'<e moutli become intertwined 

 'u a living knot of the most fantastic appearance. 



Euryale is another important genus. One form 

 has been occasionally caught on herring nets off 

 British coasts. They are sometimes called Basket- 

 fish, Medusa-headed Starfish, or Argus Starfish. 



See Forbes, British Starfishes (Lond. 1841); Hamann, 

 Beitriiffe zur Histologie der Echinodermen (Jena, 1885) ; 

 Ludwig, ' Echinodermata' in Bronn's Thierreich (in pro- 

 gress), and Morpholoyische Studien an Echinodermen 

 ( Leip. 1877-82 ) ; Lyman, Challenger Report on Ophiur- 

 oidea (Lond. 1882); Romanes, Jelly-fish, Starfish, and 

 Sea-urchins (Inter. Sc. Series, Lond. 1885). 



Stargard, the chief town of Further Pomer- 

 ania, Prussia, on the Ihna, 22 miles by rail E. by 

 S. of Stettin. Pop. 23,738. 



Star Jelly. See NOSTOC. 



Starling, a genus Stnrnus, and family Stur- 

 nidw of Passerine birds. The family is a highly 

 characteristic Old-World one, extending to every 

 part of the Eastern continent and its islands, and 1 

 even to Samoa and New Zealand, but wholly absent 

 from the Australian mainland. The Common 

 Starling (S. vulgaris) is a beautiful bird, rather 



Starling (Sturnus vulgaris). 



smaller than the song-thrush or mavis, brown, 

 finely glossed with black, with rich metallic purple 

 and green reflections, with a buff-coloured tip to 

 each leather, giving the bird a fine speckled appear- 

 ance, particularly on the breast and shoulders ; in 

 advanced age it is more uniform in colour. The 

 female is less brilliant than the male, and has the 

 terminal spots larger. Both sexes are more speckled 

 in winter than in summer. The starling is abund- 

 ant in most parts of Britain, and nowhere more 

 so than in the Hebrides and Orkneys. It is veiy 

 abundant in nearly every district of England, but 

 is less common in Cornwall and in Wales. It is 

 found in all parts of Europe, extending even to 

 Iceland and Greenland. To the Mediterranean 

 basin it is a cold weather visitor in enormous num- 

 bers ; and it is also common in the north of Asia. 

 Starlings make artless nests of slender twigs, roots, 

 and dry grass (often in company with other birds), 

 in hollow trees, in holes of cliffs, under eaves of 

 houses, or, readily enough, in boxes, which are often 

 placed for them in trees or elsewhere near houses. 

 Year after year they return and build in the same 

 spot if the nest has lieen removed. They lay from 

 four to seven pale-blue eggs, and breed twice, 

 sometimes thrice, in a season. In autumn the 

 young birds join to form flocks, which become 

 augmented by the older birds, until there is a 

 whole cloud of starlings executing aerial evolution* 

 night after night before roosting time. In winter 

 they disperse in search of food. Their food consists 

 of worms, slugs, beetles, fruit, especially elder- 

 berries, and in severe weather they eat hips and 

 haws and sandworms and small molluscs. They 



