new and rare Crustacea from Scotland. 461 



are slender ; the outer brandies are elongate and strongly 

 spiniferous ; the second johit is rather shorter than the first 

 and only two thirds the length of the last joint ; the tw^o- 

 jointed inner branch does not reach to the end of the second 

 joint of the outer branch ; the first joint is rather stouter than, 

 but little more than half the length of, the second joint; the 

 second joint bears four seta^ — the two a|)ical and one of the 

 marginal are very long, but the other is short (fig. 7) . The 

 third and fourth pairs are also slender and with short inner 

 branches ; in the fourth pair the first joint of the inner 

 branches, which only reach to about the middle of the second 

 joint of the outer branches, is so short as to be almost rudi- 

 mentary (fig. 8). In the fifth pair the inner produced portion 

 of the basal joint is somewhat cone-shaped and bears three 

 moderately long and stout plumose setaj on the inner margin 

 and two smaller setaj at the apes ; the apex of the basal joint 

 only reaches to about half the length of the secondary joint ; 

 the secondary branch is elongate-ovate in form, being nearly 

 three times longer than broad ; the apex is lengthened into a 

 narrow process, from the end of which springs a moderately 

 long seta ; on each side of this there is a subapical seta, also 

 of moderate length, while three other setae spring from the 

 distal half of the outer margin (fig. 9). Caudal stylets 

 narrow and about equal in length to the last abdominal 

 segment. 



Habitat. Port Erin, Isle of Man ; and near the mouth of 

 the Kiver Alness, Cromarty Firth ; rather rare. 



Remarks. This Laophonte has a superficial resemblance to 

 L. denticornisj T. Scott, but on closer examination it was 

 found to difier very markedly, not only from that species, but 

 from any other Laoplionte known to us. 



Idya longicornis, sp. n. (PI. XVII. figs. 10-17.) 



Description of the Sjjecies. — Female. Length 1*7 millim. 

 (yV of an inch). This form resembles Idya furcata^ Philippi, 

 in general appearance, but is larger. The antennules, which 

 are eight-jointed, are very long and slender ; the first four 

 joints are elongate, especially the third and fourth, which are 

 "nearly of equally length, the fourth being slightly longer than 

 the other ; it is also longer than all the last four taken 

 together. The formula shows the proportional lengths of all 

 the joints — 



Proportional lengths of the joints. . 30 . 40 . 45 . 47 . 7 ■ 10 . 8 . 18 

 Number of the joints 1 2 '6 4 5 6 7 8' 



