GENEEA UEOTHOE AND UEOTHOIDES. 15 



Second gnathopods as well as the first, in general character, like those of Urothoe 

 marinus, but with narrower wrists and hands. 



First and second perceopods as in Urothoe marinus, but comparatively slender, with 

 only four stout spines on the fourth joint, eight on the fifth, the finger with three or 

 four small and distant pointed tubercles. The side-plates of the first pair have five 

 spinules at the indented hind corner. 



Third perceopods. The side-plates with the hind margin only slightly indented. The 

 limb strikingly distinguished from that of Urothoe pulchella by having the fourth joint 

 not broader than the third, with about seven spines in each of its spine-rows; the finger 

 is comparatively narrow, the distal half slenderly tapering, with about seven small 

 tubercles on the front margin. 



Fourth perceopods diff'ering little from those of Urothoe marinus and other species, 

 but having the third joint shorter than the fourth, with five or six plumose setse on the 

 hind margin, the fourth joint shorter or not longer than the fifth, with three groups of 

 spines in front and two behind, the finger very slender and tapering, with about seven 

 denticles on the front margin. 



Fifth perceopods in general character like those of Urothoe marinus, but the first joint 

 not widened above, and with no conspicuous row of spinules on the upper part of the 

 hind margin; the third joint with two groups of spinules on each margin, the fourth 

 and fifth joints each with three groups on the front and two on the hind margin ; the 

 finger very slender, more than half as long as the fifth joint, with some seven or eight 

 little nodules on the front margin. The female has the front margin of the first joint 

 convex instead of nearly straight. 



Pleopods as in Urothoe marinus, but with fewer joints to the rami, the inner having 

 eleven or twelve, the outer thirteen or fourteen. 



Uropods similar to those of Urothoe brevicornis, but the rami of the two first pairs 

 smooth, the peduncle of the second pair having only one spine on the inner margin ; 

 the inner ramus of the third pair is sometimes very decidedly shorter than the outer ; 

 the number of plumose setae on the rami of the third pair appears to be too variable to 

 aff"ord a character. 



Telson not very broad, nearly as in Urothoe brevicornis. 



Length less than a fifth of an inch. 



Localities. The specimens figured were dredged in February 1889 from a depth of 

 20 fathoms, oflf Fairlie Perch, in the Clyde, near Cumbrae, by Mr. David Robertson. 

 Other specimens examined were taken by Canon Norman in dredging among the 

 Shetland Isles. The original specimen, to which the name was given by Mr. Spence 

 Bate, came from the neighbourhood of the Eddystone Lighthouse. 



