MUSEUM OF COMPARATIVE ZOOLOGY. 233 
Ophiothrix Orstedii, Lrx. 
Ophiothria Orstedii, Vid. Medd. p. 15. 1856. 
Key West, Florida, 5 specimens. 
Ophiothrix lineata ۰ 
Ophiothrix lineata, Proc. Bost. Soc. Nat. Hist, VII. p. 201. 1859. 
Off Sand Key, 20 fathoms, 7 specimens. 
The single specimen brought by Professor Agassiz more than a quarter of a 
century ago from Florida remained unique until his son again discovered the 
species, 
Ophiomyxa flaccida Lrx. 
Ophiura flaccida Sax., Journ, Phil. Acad. V. p. 151. 1825. 
Ophiomyaa flaccida, Addit. ad Hist, Oph. Pt. II. p. 138. 1859. 
Station 10, 37 fathoms, 8 specimens (young). Station 11, 37 fathoms, 11 
specimens, Station 45, 101 fathoms, 1 specimen. Sigsbee, off Havana, 175 
fathoms, 6 specimens. 
Ophioscolex purpureus Dis. & Kom. 
Ophioscole purpurea, Of. Kongl. Vet. Akad. p. 235. 44, 
Station 23, 190 fathoms, 2 specimens. 
Highly interesting as a North European species found, at no great depth, in 
the West Indies. I could see no specific difference on comparing originals 
from Scandinavia, 
SIGSBEIA. gen. nov. 
Disk small, covered with heavy plates or scales, and passing, without line of 
demarcation, into the stout arms, which can be rolled in a vertical plano. 
Teeth and mouth-papillo ; no tooth-papille. Arms bearing the usual plates, 
and in addition a large supplementary piece extending downward from the 
upper arm-plate. "Two genital openings in each interbrachial space, extending 
to margin of disk, 
This singular genus forms a peculiar group with Hemieuryale, from which it 
is distinguished by having ordinary upper arm-plates, instead of a mosaic of 
small pieces, I have already pointed out (Ann. des Sc. Nat. 1872, p. 5) that 
it belongs with the Ophiurideo, and yet Von Martens was right in saying 
that the rolling arms, passing, without line of demarcation, into the disk, sug- 
gested the simple-armed Astrophytida. Indeed, on examining the arm-bone 
joints, I find they offer a form approaching the double hour-glass joint of the 
true Astrophyton, which gives them their mobility in a vertical plane, despite 
their stiff, heavy plating. 
