950 DK. H. J. HANSEN ON OnUSTACBANS [Dec. 1, 



B. On the ext. br. of ,urp. the ciliated part occupies more 

 than the half of the exterior margin. 



S. corniculum, lir., H. J. H. {S. lacini- 



atus, Kr.) 

 S. utrinquedens, Bate. 

 8. loncjirostris, Bate. 

 To this group further belong the following species : S.proiCoTlus, 

 Bate, S. semiarmis. Bate, S.- longicaiulatus, Stimps., -S. remipes 

 (Stimps.), and S. (Sciacaris) telsoyiis. Bate. All are but larv£e. 



Gboup II. 



Mxp? considerably or much lomjer ilian trl.^, its 4 proximal joints 

 considerably or (ffenerally) very much incrassated or partially almost 

 inflated in 2)roportion to the joints in trl?, its two distal joints with 

 very short bristles or totally naked along the one margin, the 

 sixth joint with a number of spines very different in length along 

 the other margin, and a feebler armature may also be found on the 

 fifth joint. 



A. The adult and the older larvffi with two branchiiB above 



trP., and the sixth joint of mxp.^ divided into 5 subjoiuts. 

 The adult with a comb of very numerous short spines 

 along the one margin of the sixth joint aud of the distal 

 part of the fifth of mxp.''' The larvae with short eye-stalks. 



{*S. hens en i (Ortm.). 

 S. sargassi, Ortm. 



B. The adult and tlie older larvaj with one branchia and a 



lamella above trF., and the sixth joint of mxp.^ divided 

 into 4 or 6 subjoints. The adult without any comb on 

 mxp.^ The larva) with moderately long or very long eye- 

 stalks. (The edwardsii-'^vou.Tj).') 



a. On the ext. br. of nrp. the exterior margin is ciliated in 



the whole length or (in the larvae) at least in c. -f^ of 

 the length.' 



J *iS. e d w a r d s i, Kr, 



[ S. oculatus, Kr. 



b. On the ext. br. of urp. the exterior margin is ciliated at 



most ill g of the length, 

 a. The same exterior margin is in the larva) ciliated at 

 lea.st in |, in the adults in more than f of the length. 



{*S. vigil ax, Stimps., H. J. il. 

 S. parvidens. Bate. 

 *S. p eneri n Jc i. Bate, H. J. H. 

 j(3. The same exterior margin is ciliated in less than | of 

 the length. 



*S. incertus, n, sp. 

 *S. hali a, Faxon. 

 S. armutus, Kr. 



' Hero and in the following part of llio tabiilai- view I cannot incliido Iuitie 

 shorter tlian 9-10 mm. in length, as the character employed altera iu the 

 youngest stages (see later on). 



