found in the Firth of Forth. 365 



MuNNA KROYERi. (Aftht.) Plate VL iig. 2. 

 With the eyes extremely prominentj and with the whole 



body very spiny. 



Description. — The whole animal of an ochrey-brown colour^ except the 

 reticulated portion of the eyes, which arc black. The head is lar^e, 

 rounded anteriorly, and slightly pointed in the middle. The palpi of 

 the external maxillaj are seen projecting in front of the anterior edge, 

 and they are always in motion. The dorsal surface of the head is quite 

 smooth, and die internal or superior antcnnec arise from it within the 

 margin, and a little anterior to the eyes; they are extremely curious, 

 and are composed of a peduncle of three articulations, and of a double 

 multiarticulatc setaceous portion, which arises from the last joint of the 

 peduncle; these are very slender, and incline towards one another at 

 their extremities (Plate vi. fig. 1). The whole organ is equal in length 

 to the two first joints of the inferior anlennai and the proximal half of 

 the third joint. The external antennaj arc much produced, being consi- 

 derably longer than the body; the peduncular portion is composed of 

 four joints, the setaceous portion is multiarticulatc. Two large blood- 

 vessels are seen running through these organs. 



The eyes are large and pedunculated, but quite immoveable ; the re- 

 ticulated portion is small, and is almost altogether confined to the 

 lower surface. The first six thoracic segments of the body arc almost 

 all equal ; the seventh is obsolete. The first pair of legs are prehen- 

 sile, and tlie mechanism is rather curious (Plate VI. tig. 5) ; the fourth 

 joint is very large and rounded, the inferior angle of its distal extre- 

 mity is armed with four large and strong teeth, two of which are large, 

 the other two being smaller ; the fifth joint is not so large, and is reni- 

 form ; the sixth joint is long and pointed, bearing at its extremity a strong 

 claw. The following six pair of feet are ambulatory (Plate YI. fig. 10). 

 They are very spiny, and the last joint is armed with two strong claws, 

 which are not placed in the usual way, but with the one above the 

 other; the superior is largest and strongest. The abdominal portion 

 of the body (Plate VI. fig. 14) is composed of two segments. The 

 first, which is largest, is of a square shape, and is armed with two 

 strong spines at its posterior angles. The last segment is almost tri- 

 angular, the apex being directed posteriorly, two small styles arise from 

 each side of the apex. All the external margins of both of these seg- 

 ments are thickly fringed with minute hairs and spines. 



The abdominal branchire are almost semicircular, and each of them 

 is armed on its internal edge with a small appendage. Length of body 

 one line ; span of legs three lines. (Plate VI. fig. 6). 



I dedicate this species to M. Kroycr, the original discoverer 

 of the genus, and a naturalist who has added much to our 

 knowledge of the Crustacea of the north of Europe. The M. 



