STATE GEOLOGIST, 149 



above in the larger lakes. It appears to be but a modified condi- 

 tion of the above species, from which it differs in its slender form 

 and especially in the very slender caudal stylets. The outer caudal 

 seta is reduced to a short ciliate thorn. The fourth foot is also 

 modified by the great enlargement of the spines and the reduction 

 of the setae. The number of the setge is the same, but they are 

 differently disposed. The form of the operculum vulvae is also 

 slightly different. 



(?) Sp. 11. Cyclops uniangiilatus, Cragin. 



Cyclops unianuxilatus, Cragin. A Contribution to the History of Fresh-water Cope- 

 pocla, p. 6. 



Cragin was not conversant with the description of C. parens, with, 

 which his description agrees save in one point. It differs from C. 

 parens in having three inner setae on the terminal joint of the outer 

 ramus of the first foot. It would be of&cious to suggest a possible 

 oversight here, but C. parens has only two in type specimens 

 {though in all this group the corresponding ramus of the second 

 Joot has three setas), so that at present the two must be kept dis- 

 tinct. 



Sp. 12. Cyclops scutifer, Sars. 



e 



Not having identified this and the following species it will be 

 best to quote the descriptions. 



C. strenuo affinis. Cephalothorax sat elongatus, segmentis ultimis duobus in femina 

 ad latere valde prominentibus inque processos exeuntibus laminaves et hyalinos utrin- 

 que inter se contiguos, quare thoracis pars posterior tamquam clypeo fornicato quad- 

 rangulari obtecta esse videtur. Segmentum 1-mum abdominale ad basin valde dilata- 

 tum latitudine quam ad marginem posteriorem dupio majore. Eami caudaies segmen- 

 tes antecedentibus duobus junctis parum longiores, introrsum ciliati, setis apicalibus 

 brevissimis, intermediarum interiore ceteris multo longiore. Antennae l-mi paris 17- 

 aiticulatae, reflexse segmentum 2-dum corporis superantes setis plurumque longis obsi- 

 tfe. Pedum structura eidem in C. strenuo similis. Articulus scilicet ultimus rami exter- 

 ioris pedum natatoriorum setis 5 instructus in paribus anterioribus duobus 3, insequen- 

 tibus duobus 2 modo aculeis marginis exterioriis armatus ; aculeorum apicalium 

 rami interiores pedum 4-ti paris exterior brevis et rudimentaris. Pedum 5-ti paris arti- 

 culus ultimus sat magnus artlculo basali parum minor extrorsum sparsim pilosus in- 

 trorsum aculeo armatus ciliato setaque longa terminali. Sacci oviferi parvi globosi 

 abdomen magna ex parte obtegentes. Longit. circit. 134 mm. 



Sp. 13. Cyclops abyssorum, Sars. 



C. strenuo et scutifero sat affinis. Cephalothorax ovatus antice obtuse truncatus, seg- 

 mentis parum ad latera extantibus. Kami caudaies longi et tenues satisque divergen- 

 tes, longitudinem segmentorumantecedentium 3 superantes, setis apicalibus lengioribus 

 intermediarum interiore duplam longitudinem furcse superante, exteriore quam ilia 

 parum breviore. Antennae l-mi paris 17-articulatae longae et fere rectae distincte posticl 



