STAn-FISHES. 157 



The famil_y BrisingidjE iuchuk's only two known species, liotli inhabitants of deej) 

 water, where they have an exceedingly wide distribution. The genus approaches 

 J'l/c/wpodkc and Crossasfer, but in appearance is intermediate between the ophiurids 

 and the star-fishes, since it has a distinctly circumscribed disc like the former, 

 thouoh the hing arms are soft as in the hitter. jBrisinr/a endecaommos has eleven 

 .arms, which ai-e nearly smooth, while the nine to thirteen arms df /). roronata have 

 tr;nis\erse crests of spines. The arms are sometimes a foot long, they ,are narrow at 

 their insertion into the disc, enlarge considerably towards the middle, where the 

 ovaries .are develo]>t'd, ami tapei- tlieiuH' to the tip. 7>. c"W'0^j«<(6 has a single genera- 

 tive or^an, with a single o|ieHiiig, un each side of each arm, while li. oiidixacnenws 

 has a u'reat nunilier of separate sni.ill urgans, each with its own ojjening, in a similar 

 position. The w:iter-feet are fui'iiished with sucking-discs. I'ows of long spines 

 covered with soft skin border the ambnfacral grooves; this skin is full of small 

 pedicellariu?, and groups of pedicellaria' ai-e scattered over .arms and clisc. The 

 cre;iture is extremely fragile, and always breaks to jjieces before it can be handled. 



The Pteeastekid.e arc furnished with groups of diverging si)incs, on the tips 

 of which a membrane is carried. Ilijinenaster pelluckhts was first dredged in five 

 hundred fathoms off the north <if Scotland, and it has since l)een found that, with 

 pt'rhaj)S the exception of Arclmsfi:); Ili/menastev is the most widely distributed geinis 

 of ileeji-water asteri<ls, vni-ying from four hundred to (wo tliousand five hundre<l 

 fathoms. 



Illjmenaater iiobillK is rathia- a large st.ar-fish, tiai im'lies across. The five arms, 

 each two inches wide, are united to each other by a lnnad web attacheil to the outer 

 row of the spines which fiingx^ the amlndacral groo^ e, thus transforming the animal 

 into a large jientagoii. 'I'he entire upjier surface, the web excepted, is set with 

 bunches of four to six diverging spines about an eighth of an inch long. These spines 

 support, dear of the surface of the disc, a tolerably strong membrane, like the canvas 

 of a tent. Something similar to this nvt'mWm PtemMer. In the centre of the back 

 this arrangement is modified to form a brood ])0uch for the young. From five 

 calcareous supports, arising from the ambidacral plates below, spring a double series 

 of spines, the outer series of three or four <liverging in the onlinary way beneath the 

 tent cover, while the inner series of six or eight neiMl inwards, and have a special 

 membrane stretched between them in such a way that each sei-ies forms a fandike 

 valve, the spines closing when the valve is closed .and separating when it is opened, 

 in this central jioucli tlu' young are carriivl. This species was taken in eighteen 

 hundred fathoms, about eleven hundred miles southw^est of Cape Otway, Australia. 



Korethraster hisx>idits was dredged near the Shetland Isles. It is a small star-fish 

 with the whole of its u]i]U'r surface covered with long spines (jiaxillai) like sable 

 brushes, masking its true outline. T^ows of delicate, spoon-.shaped s))ines border the 

 anibulaci-al grooves. Another species of this genus, K. pal>natns,hns been dredged 

 in the Caribbean Sea. 



Pteranter is the priiuapid genus of this essentially deep-watci- family. In P. 

 /iia/dpes, of the Norwegian seas, there are four rows of water-feet, as in Asfen'as. 



The AsTROPECTixii)^ are forms with long rays ending in a point, thus resembling 

 in general shajie the Asteridre, from which they differ in having two rows of ambula- 

 cral tentacles, which are usually without sucking discs at their extremity, and also in 

 the character of the skeleton, which is formed, at least in the dorsal region, of con- 

 tiguous ossicles, often shajjcd like an hour-glass, and bearing tubercles which are 



