ISOPODA or THE 'LIGHTNING' AND OTHER EXPEDITIONS. 95 



terminations, while the spines of the palm are mucronately attenuated at their apices, 

 the attenuated flexible distal portions being exquisitely pectinately ciliated (see enlarged 

 figure). 



Last legs (i. prj^) slender ; basos long and narrow, with only 6-7 short and delicate 

 plumose setffi on the hinder margin ; ischium very short, naked ; meros about three 

 times as long, with only two or three small cilia at the termination in front ; wrist 

 equal in length to two preceding joints combined, with about ten long cilia on the 

 front margin ; propodos a little shorter than carpus, with four cilia on front margin, 

 these cilia are suddenly attenuated at their apices, and a series of minute sharp 

 spinules, which are bulbously enlarged at the base, fill up the spaces between the 

 origins of the cilia. These spinules do not actually touch each other, they are pecti- 

 nated on the sides as in other allied species ; they do not extend round the termination 

 of the joint, but at the termination of the hinder margin there is a group of minute 

 pectinate spinules, together with two long and one short flagellated spines. Dactylus 

 very long and slender, with two cilia on the back, and one minute denticle near the 

 base on the inner side ; its unguis very long. 



Pleopoda (i. j)J])) largely developed, with long peduncles. 



Length half an inch. 



Dredged off the Portuguese coast, in 740 fathoms, ' Porcupine,' 1870, Station 17 a, 

 lat. 39° 39' N., long. 9° 39' W. ; also off the south-west coast of Ireland, in 90 fathoms, 

 'Porcupine,' 1869, Station 6, lat. 52° 25' N., long. 11° 40' W. 



9. Apseudes gracilis, n. sp. (Plate XX.) 



The carapace (i. d) has the frontal margin produced into a long slender acute rostrum, 

 which is half as long as the basal joint of the upper antennae, and has a bulbous process 

 on each side at its origin ; ocular processes or alae having their outer sides prolonged 

 into an acute spine-like termination projecting forwards and slightly outwards. On 

 each side of the carapace, at the junction of the first coalesced segment of the peraeon 

 with the cephalon, there is another pair of spinous processes closely assimilating in 

 form to those of the alae just described. 



The peraeon (i. l) has the segments remarkably long, more produced than in any 

 other known species, especially the last four; each segment bears a pair of lateral 

 acute spinous processes, and in front of these a pair of small tubercles, while on the 

 ventral surface there is a large acute curved spine near the hinder margin, and near the 

 front margin a small tubercle bearing two or three minute cilia. The epistoma is 

 tumid, arched, carinate, and armed with a small spine near the mouth. 



The pleon (i. l) is of great length, the five front segments subequal, and each as long 

 as the first free segment of the peraeon ; epimera only slightly produced, terminating 

 in small spines, a central ventral spine on each segment ; last segment (i. pl) as 

 long as the preceding three, having a number of minute tubercles about it, termination 



q2 



