OPHITJEOIDEA FEOM THE KOKEAN SEAS. 



465 



process, on the sides of wliicli are the generative slits, and all 

 project orally so as to be very close to the jaws. The side mouth- 

 shields are very small, narrow, and triangular ; they are separate 

 within, and form a blunt process on the edge of the lower arm- 

 plate without. 



There are four mouth-papillse to eacli jaw-angle ; and there is 

 an upper tentacle-scale, on either side, with its top close to the 

 jaw. The inner pair of mouth-papillae are separate, large, pine- 

 apple-shaped with a point, and their attachment to the jaw 

 is somewliat constricted : the outer pair are subspinous, long, 

 compressed, often bent, and project downwards, being attached 

 close to the junction of the jaws and the side mouth-shields. The 

 jaws are short, stout, straight, and parallel ; and the teeth are 

 large, broad, short, and rather square at the edge. The tentacles 

 of the oral apparatus are large and long. 



Tlie first lower arm- plate is very small and rudimentary ; and 

 the second to the fifths which are covered by the disk, are longer 

 than broad, rectangular, with the corners rounded ; the inner and 

 outer edges are slightly slanting, and the plates are slightly sepa- 

 rate. In mid arm the plates are longer than broad, slightly 

 swollen at the sides, straight without and also within, where there 

 is often a faint notch or a re-entering distal curve. Towards the 

 end of the arms the plates are longer, more swollen at the sides, 

 and rather constricted within and without from the inward ex- 

 tension of the side arm-plate. 



The upper arm-plates are broader than long in mid arm, and 

 rather longer than broad near the disk and at the end. The first 

 is small, and about as long as broad ; it is heart-shaped, and the 

 distal curve, the largest, is bold, whilst the opposite end is more 

 angular ; the second, overlapped slightly by the first, is longer and 

 larger, as are the third and fourth ; their greatest breadth is 

 orally, where the broad curve is. A faint longitudinal coloured 

 ridge is seen near the outer edge. The plates gradually increase 

 in size, and become broadly oval in shape; and the side arm- 

 plates, large on the side of the upper part of the arm, only permit 

 them to touch by a small edge. At the end of the arm the plates 

 are broadly curved w'ithout, and rather small and angular 

 within. 



The side arm-plates are large, and form much of the tall sides 

 of the arm and part of its upper surface, although they do not 

 absolutely meet until close to the end. Their free edge does not 



JjlKS. JOUEN. — ZOOLOGY, VOL. XIV. 34 



