32 
THE VOYAGE OF H.M.S. CHALLENGER. 
2. Anchors of one hind. 
а. Anchor-plates with low ridges or prominences between the holes. 
Synapta distincta, von Marenzeller, 1881. 
Anchor-arms with minute serrations. Anchor-plates roundish oval, with incomplete 
niargin and numerous smooth holes ; no handle. Miliary granules cruciform, 
with the short arms spinous. 
Habitat. — Miya in Japan (von Marenzeller), Amoy (Ludwig). 
б. Anchor-plates smooth, without ridges. 
Synapta autopista, von Marenzeller, 1881. 
Anchors short and robust, with a few larger and smaller serrations at the ends of the 
arms. Anchor-plates asymmetrical, roundish angular, with uneven incomplete 
circumference and numerous smooth holes ; no handle. Miliary granules, 
X -shaped or plate-like with a few holes and knobs. 
Habitat. — Miya in Japan (von Marenzeller). 
This species does not seem to be well defined. Von Marenzeller remarks that it bears 
in some respects a certain resemblance to Semper’s Synapta molesta. 
Synapta hispida, Heller, 1868. 
Anchor-arms smooth. Anchor-plates oval with slightly uneven margin and numerous 
(about 28) smooth holes; no handle. Present some similarity to Synapta digitata 
Habitat.— LeAao. (Adriatic Sea), Heller. 
The following species are quite unknown as regards internal and external organisa- 
tion : — 
Synapta incequalis, Hutton, 1872. 
Habitat. — New Zealand (Hutton). 
One of the anchor-arms being much longer than the other, this species may possibly 
be nearly allied to Ludwig’s Synapta asynimetrica. 
Synapta bachei (?), Ayres, 1854. 
Habitat ? 
{f) Synapta vivipara [Synaptida), (Ersted, 1851 ; Ludwig, 1881. 
Habitat. — West Indies ((Ersted). 
Nothing is known of this animal excepting that it is provided with anchors, and is 
viviparous. Agreeing with the views of Ludwig, I cannot consider a genus 
justified only on account of its representatives being viviparous. Therefore I 
think it most proper, for the present, to refer the species of (Ersted to Synapta 
or Cliirodota, and to omit his genus Synaptida. 
