146 TWELFTH ANNUAL REPORT. 



handl. naturwiss. Vereine zu Bremen. Bd. vii, 1. Heft, p. 62) 

 that C. gigas is but a greatly enlarged form of C. brevicornis. See 

 also American Naturalist, May, 1883, p, 491^ where I have expressed 

 a similar opinion regarding the American form. 



A part of the original description of C. iugeus is here given. 



Thorax large; abdomen rather slender; stylets slender, with the 

 lateral seta well towards the end; second and third setae alone long, 

 weakly pectinate; last joint but one of abdomen sometimes toothed 

 along the distal, under margin; jaws with large teeth; antennee very 

 short, not reaching to the base of the first cephalothoracic segment; 

 formula — i::— — ir^-^ — w-^w^v^^-^^rr; ftfth foot two-jointed, the 

 proximal joint very broad with a strong spine; second joint C3'lindri- 

 cal with a long seta and a very short spine near the end; oper- 

 culum vulvas somewhat heart-shaped; egg-sacs oval-elongated, 

 reaching beyond the end of abdomen; length 4 mm., including 

 stylets and setae. 



Sp. 4, Cyclops leiickartii, Claus. 

 ? C. crassvLS, fischee. 



Is said to be elongated and slender; the antennae are nearly as 

 long as the first three segments. The fifth foot is like the smaller 

 forms of the above, but the second joint has only one spine. The 

 proportions of the caudal setae are very much as in the above. 



Rehberg denies that Sars' identification of this species so briefly 

 described by Claus is correct; his description is therefore copied. 

 Sars refers also with a query to C. obsoletus, Koch. 



"Cephalothorax ovatus autice sat attenuatus, fronte leviter truncata, secmento ulti- 

 mo parvo vlxque ad lateia exstante. Segmeutum abdominale l-nium sub-cylindricum 

 aiitlce quam postice parum latins. Rami caudalisbrevisculi longitudinemsegmeutorum 

 antecedentium duorum non attiugentes setis apicalibus sat lougis, externa furcae 

 longitudinem soquante dimidiamque Interni, intermediaium interiore altera aliquauto 

 longiore longitudinem abdominis fere requante ; seta niarginis exterioris ab apice sat 

 teniota. Antennse ]-mi paris IT-articulatpe, longiE et apicem versus attenuatse, 

 reflexBC segmentum i-tum corporis fere attingentes ; 2-di pans quam in speciebus 

 ceteris longiores. Maxillarum 2-di paris margo posticus subtillssime crenulatus. Pedes 

 5-ti paris bi-artlculati, articulo ultimo bisetoso. Rami pedum natatoriorum omnes 3-ar- 

 ticulati ; articulus rami exterioris intus setis 3, extus aculeis 2 instructus. Lamina par- 

 tes basales pedum 4-ti paris conjugens utrinque in processum acuminatum exit. Rami 

 Interioris articulus ultimus insolito modo in longitudinem extensus in pedibus 4-ti paris 

 aculeis apicalibus 2 subajqualibus armatus. Saccioviferi rotunda to-ovati ab abdomine 

 sat exstantes. Longit. parum supra 1 mm." 



Sp. 5. Cyclops lacustris, Sars. 



Cephalothorax sub-ovate, truncate in front. Abdomen nearly 



