OF THE MERGTJI ARCHIPELAGO. 



91 



project over the arm and are close ; the outer sides overlapped b y 

 scaling. Genital plate slender and long, rod-like, articulated 

 with the radial shield, and having a slight expansion at its inner 

 part over the arm ; it arches into the longer and equally slender 

 genital scale. The aboral ends of the united genital plate and 

 scale overhang the arm and nearly touch their neighbours at the 

 median line. 



Generative openings large. Interbrachial spaces below with 

 a plain skin, the only scaling being on the side of the genital slit 

 and on a line with the oral end of the generative scale, and it 

 consists of a close row. 



Mouth-shields longer than broad, broadly rounded without and 

 narrower and more angular within. Side mouth-shields large, 

 broad at the side of the arm, and long from side to side in front 

 of the mouth-shield, only separated by the very small first arm- 

 plate. 



Jaw-angles broad and short, with four mouth-papillae on either 

 side, of which one is stout and immediately below the true teeth, 

 the next is small, and the following pair are frequently united. 

 These eight papilla?, which are very constant, project downward. 



The arms are long, filiform, and slender, but they do not diminish 

 much in breadth ; they are rarely otherwise than straight, and 

 usually three are in one direction, and all look like stiff wires 

 rather than threads. Lower arm-plates : the first is very small, 

 incurved orally, and convex at the edge without, touched on either 

 side by a side mouth-shield ; the second is much larger, is quad- 

 rangular, but longer than broad, broadest orally, and convex at 

 the edge without. Beyond the disk the plates are much longer 

 than broad, slightly broadest at the inner edge, which is convex, 

 and with sides straight and slanting to the narrower outer edge, 

 which is incurved. In mid arm the length preponderates over the 

 breadth, and the breadth is greatest at the edge within, and this is 

 convex, w r hile the edge without has a decided incurve. At some 

 distance from the disk the plates are not close, on account of the 

 side arm-plates coming in. 



Upper arm-plates broadly triangular, point without, angles at 

 the sides and without rounded off ; oral edge broad and slightly 

 curved within. Usually with a small median ridge. The median 

 part of the first six or eight upper arm-plates deficient. 



Side arm-plates large, projecting obliquely, meeting, not far 

 from the disk, on the underside of the arm broadly, and thus 



