139 



dened. The young ready to emerge from the body through 

 the slits are very soft, and can consequently squeeze through 

 a small space; the slits, however, in this species are large. 



The following descriptions are from the male in each 

 case, except where otherwise stated. 



Family SPH^ROMID^. 



Subfamily SpH^ROMiNiE. 



Group Hemibranchiat^, Hansen. 



Genus Cymodoce, Leach. 



Cymodoce longicaudata, n. .sp. 



Plate iii., figs. 1 to 11. 



The body is little convex, the tendency to curl up much 

 reduced, becoming slightly narrow towards the head. 



The head is arcuate in front, and considerably longer 

 than the first thoracic segment. The eyes are large, pro- 

 minent, and wedge-shaped. There is a median rostral pro- 

 jection, which is rather large and terminally obtuse. 



The first thoracic segment is rather shorter than those 

 which follow, the rest are short and subequal in length. 

 The epimera, except the ones belonging to the last segment 

 of the thorax, project laterally, and are very conspicuous 

 viewed from above. They are sickle-shaped backward and 

 very acute, and are all — except the first — marked off from 

 their respective segments by distinct sutural lines. The 

 last segment has epimera rounded and scarcely projecting. 



Four fused segments are indicated on the anterior por- 

 tion of the pleon ; the first terminates laterally under the 

 side of the preceding segment; the second has an acute 

 lateral projection, similar to those of the thoracic segments; 

 the fourth has the median portion of the posterior margin 

 slightly arcuate, with the usual notch on each side. The 

 terminal segment of the pleon is dome-shaped, and has an 

 acute! lateral projection ; behind this the surface is strongly 

 depressed until the basal portion of the median posterior 

 spine is reached. The posterior notch is bounded by two 

 acute projections, with the median spiniform process large 

 and reaching much beyond them ; this process is dorsally car- 

 inate and very acute. 



The epistome is well developed; its lateral limbs are 

 subacute. 



The rather large basal joint of the antennule has the 

 anterior side of the distal notch scarcely j^roduced, but on the 

 posterior side the projection is very acute, curved, and 

 reaches nearly to the end of the second joint, as in Circeis. 

 The second joint is more than half the length of the first 



