TSOPODA OF THE 'LIGHTNING' AND OTHEE EXPEDITIONS. 101 



long cilia on the back, and short graduated spines with intervening cilia on the palm ; 

 the slender finger is set well back, and has an adjoining spine close to it, and of almost 

 equal length. 



The second peraeopods {i-prir) have the basos armed with two strong spurs on the 

 upper margin. 



The third perseopods {i.prp^ and i.prjf) are distinguished by a group of finely 

 biserrate spines upon the hand surrounding the base of the finger. 



The following pair (i. pr])*) have a spur on the back of the basos. Both this and the 

 last pair (i. prj;') have the wrist longer than the hand, and fully ciliated on both 

 margins, the hands straight ; the finger slender and shorter than the hand. 



The uropods have their peduncles curving a little inwards and distally dilated ; the 

 longer branch consists of eight or nine articulations, which are alternately longer or 

 shorter, but the first two much stouter than those which follow ; the shorter outer 

 branch is made up of three very narrow articulations, of which the last is the longest. 



The length of the animal (antennae and uropods not included) is three tenths of 

 an inch. 



In the female the gnathopods differ greatly from those of the male, the sex which 

 we have described, and are very like in form to the gnathopods which we have figured 

 of S])hyrapits anomalus ; the form of the segments of the pleon will at once distinguish 

 it from that species. 



This species was dredged by the 'Porcupine' in 1869, in 420 fathoms, to the south 

 of Eockall, Station 23 a, lat. 56° 13' N., long. 14° 18' W. 



3. Sphtrapus Ai^OMALUS, G. O. Sars. (Plate XXI. fig. ii.) 



1869. Apseudes anomalus, G. 0. Sars, Undersogelser over Christianiafjoi-clens Dybvandsfauna, 



p. 45. 

 Sphyrapus anomalus, G. 0. Sars, "Isopoda chelifera," Archiv for Mathem. og Naturvid. 1881, 



Bd. 7, p. 19. 



Head and sides of perseon and pleon (ii. l) not spined. Last three segments of 

 peraeon much constricted anteriorly. First segment of body (head and first and second 

 of peraeon coalesced) smooth above, side margins evenly arched, produced in front into 

 a large frontal lobe (ii, c), terminating in a simple rostrum, the extremity of which is 

 minutely nodulous ; at the sides there is also the small ophthalmic process at the base 

 of the upper antennae. Pleon having the sides of the segments rounded, with a very 

 minute point at hinder corner. Telson subtriangular (ii. urp), extremity not produced, 

 terminating obtusely, with a little dorsal tubercle bearing two small setae. Upper 

 antennae (ii. aa) having a secondary flagellum of three articulations. Lower antennae 

 having last joint of peduncle very long, the flagellum equal to it in length and com- 

 posed of four articulations. First gnathopods (ii. gn^) with the hand as long as the two 

 preceding joints, elongated-ovate ; finger and thumb long, forcipiform. Second gnatho- 



VOL. xii. — PART IV. No. 4. — October, 1886. E 



