OPHIUROIDEA 243 



made as to which of the known forms of Ophiuroid larva) may 

 belong to this species. 



In British seas this species is known only from the North Sea 

 coasts, from the Shetland Islands to Durham. It is not known 

 from farther south on the European coasts ; towards the north 

 it goes as far as Spitzbergen and the Kara Sea. Also known from 

 Greenland and the Atlantic coasts of N. America to Cape Cod. 

 Possibly the North Pacific 0. maculata Ludwig is the same species 

 as 0. robusta. Bathymetrical distribution ca. 6-450 m. (excep- 

 tionally as much as 1000 m.). 



6. Ophiura carnea M. Sars. (Fig. 131, 3-4.) 



(Syn. Ophioglypha carnea (M. Sars) ; Dictenophiura carnea 



(M. Sars).) 



Disk somewhat high, covered with rather coarse scales of 

 uniform size ; primary plates indistinct. Radial shields contigu- 

 ous distally, very small ; in larger specimens scarcely larger than 

 the other scales. Arm combs almost vertical, consisting of ca. 12 

 small papillae ; the inner comb fairly distinct. Two to three dorsal 

 plates in the notch, the inner one almost vertical and divided 

 by a median furrow into two lateral halves. Arms not roof- 

 shaped arched. Dorsal plates contiguous only on the proximal 

 joints ; somewhat elevated at their outer edge, which is strongly 

 convex. Ventral plates very small, triangular, with convex outer 

 edge, separate in the whole length of arm. Three very small arm 

 spines, placed at equal distances from one another. The proximal 

 pore pairs with tw^o small tentacle scales ; farther out there is only 

 one tentacle scale. Mouth shields large, longer than broad, reach- 

 ing more than half-way to the edge of disk. Three to four mouth 

 papillae, the two outer ones somewhat broader than the inner 

 ones. Colour in life, beautifully pink or reddish-brown. It is a 

 small but rather robust form, which scarcely grows beyond a 

 size of 7 mm. diameter of disk. Arms short, only ca. twice the 

 diameter of disk. 



Development unknown ; but judging from the small size of 

 the eggs it may be expected to have a pelagic larva. 



In British seas this species has been found only off the west 

 coast of Ireland, 215-ca. 400 m. (" Helga "). It is distributed 

 elsewhere from the Trondhjem Fjord on the Norwegian coast to 

 the Azores and Cape Verde and the Mediterranean. The bathy- 

 metrical distribution is ca. 50-1260 m. 



