THE YOUNG 



is a rare bird in the neighbourhood of 

 Huddersfield. 



Whinchat. — First seen, April 14, 1870; 

 May 5, 1873 ; April 25, 1874; April 10, 1875 ; 

 May I, 1880. 



Wheatear. — First seen, April 14, 1870; 

 March 24. 1872; April 5, 1873; April 10, 

 1874; April 22, 1878 ; April 4,1880; April 

 2, 1881. 



Nightingale. — May 14, 1875. Went to 

 Mollicar Wood and had the pleasure of 

 hearing the Nightingale in full song. It 

 commenced to sing May 5th, and has sung 

 every night since. It commences to sing 

 about ten oclock and continues until four in 

 the morning." (The nightingale is very rare 

 in this neighboughood, and this is the 

 only one which has been heard for many 

 years.) 



Blackcap. — (No date) " I received a very 

 fine specimen of the Blackcap Warbler 

 (Sylvia atricapilla) which a friend of mine 

 had shot on the 26th of January, 1866. It 

 is an adult male bird in very fine plumage, 

 and I think it is unusual for it to be so very 

 far north in January. It was feeding with 

 some sparrows on a manure heap at Almond- 

 bury Bank." 



Garden Warbler. — First heard, May 3, 

 1878; May 16, 1874; May 16, 1875. 



Sedge Warbler. — First heard, May 4, 

 1873 ; May 16, 1874. 



(Tq be continued.) 



THE ANATOMY OF A 

 SEA-URCHIN. 



By J. W. Williams (Univ. Dunhelm), 



Honorary Member 

 Bolmere Naturalists' Society, &c., &c. 



The skeleton of a Sea-urchin consists of a 

 test or shell composed of five or six-sided 

 calcareous plates arranged in ten rows or 



NATURALIST. 139 



zones. These plates are not all of the same 

 size, but occur alternately large and small, 

 the latter being perforated with small holes 

 for the emission of the tube-feet, and on this 

 account are called ambulacral plates. Be- 

 sides these plates the mouth is covered with 

 a membrane of leathery texture, in which 

 are imbedded numerous small calcareous 

 pieces, and the same obtains with the oppo- 

 site or oboval end. The former are called 

 oval and the latter anal plates. Another 

 series of plates occur — the so-called genital 

 and ocular plates at the apex and the anal 

 opening of the test. The genital plates are 

 five in number and pentagonal in form, each 

 of which is perforated by a duct from the 

 genital organs. One of these plates supports 

 a protuberance called the madreporiform 

 tubercle, which contains a number of minute 

 openings through which the organs connec- 

 ted with the vascular system pass. The 

 ocular plates, on the other hand, are smaller 

 and are situated at the top of the ambula- 

 cral areas between the genital plates. Each 

 of these is perforated so as to hold the 

 ocellus or eye-spot. 



The Sea-urchin belongs to the class Echin- 

 odermata, so-called because the plates are 

 covered all over with numerous spines S3 as 

 to give it a hedgehog appearance (Gr. echinos, 

 hedgehog; derma, skin), and to the sub- 

 kingdom Annuloida, because the body does 

 not consist of a number of segments like the 

 Annulosa, and because a series of canals 

 known as the water vascular system are 

 always present. 



Situated among the spines I have referred 

 to, are numerous peculiar organs called 

 pedicellarise, which contain at their extremi- 

 ties three, sometimes four claws, the function 

 of which seems to be the removal of any 

 foreign matter from the spines. 



Locomotion takes place in an exceedingly 

 curious manner. I have spoken of the tube 

 feet. These are protruded through the 

 ambulacral areas — reaching to a far greater 



