114(3 THE VOYAGE OF H.M.S. CHALLENGER. 



Klassen unci Ordmmgen, Bd. v. Abth. ii. p. 496, 1886. In all three definitions the upper 

 antennae are said to be without a secondary appendage, although Gosse, in describing the 

 antennae of the type species, had rightly observed " superior pair furnished with a minute 

 appendage at the base of the lash." Spence Bate describes the three posterior pairs of 

 peraeopods (in his specific accounts) as subequal, but in fact the third parr is considerably 

 shorter than those which follow. Gerstaecker in the generic definition says of these three 

 pairs, " die drei letzten Paare verlangert, mit erweitertem Schenkelglied," whereas in fact, 

 attention should rather be called to the comparative narrowness of the first joint. The 

 name Dryope will require alteration, being, according to Scudder's Nomenclator Zoologicus, 

 preoccupied among Diptera in 1830. 



The generic name is derived from Dryope, the genus above mentioned, and elSos, 

 likeness. 



Dryopoides westivoodi, n. sp. (PL CXXIL). 



Rostrum very small, acute ; lateral lobes more advanced, distally rounded, not broad, 

 the head squared below the lobes ; the back of the animal flatly rounded ; the postero- 

 lateral angles of the first three pleon-segments rounded ; the fourth segment of the pleou 

 as long as any of the three preceding segments, having a feathered cilium on the hind 

 margin at either side, not showing any transverse dorsal depression ; the fifth segment 

 short ; the sixth segment without any dorsal arch, so that from above the telson appears 

 as if attached to the fifth segment. 



TJie Eyes round, with about seventy ocelli in each, situated close to, rather than on, 

 the lateral lobes of the head. 



Upper Antennse longer than the lower, but with much shorter peduncle. The first 

 joint rather longer than the head, slightly curved, with two groups of spines on the 

 under margin ; the second joint longer than the first, also slightly curved, with slender 

 spines on the lower margin and some spinules on the upper ; the third joint little more 

 than a quarter the length of the second ; the flagellum of about thirty joints, the distal 

 longer than those nearer the base, all together much longer than the peduncle ; the 

 secondary flagellum not visible on the outer side of the antennae, consisting of a slender 

 joint, with a minute terminal joint, the two together not so long as the first of the 

 primary. 



Lower Antennse. — The first two joints short, the gland-cone deeurrent, but very 

 short ; the third joint a little longer than the united first and second, with two groups 

 of spines on the under margin, and two of shorter less slender spines near the upper ; 

 the fourth joint long, a little curved, longer than the second of the upper antennae, 

 slightly widening distally, carrying several groups of spines on both margins ; the fifth 

 joint longer than the fourth, with numerous spines; the flagellum not so long as the 



