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 setae is the same, but they are 

 differently disposed. The form of the operculum vulvae is also 

 slightly different. 



(?) Sp. 11, O5 clops uniangulatiis, Cragin. 



Cyclops uniangulatus, Cragi^". A Contribution to the History of Fresh-water Cope- 

 poda, 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 officious 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 

 foot has three setae), so that at present the two must be kept dis- 

 tinct. 



Sp. 12. Cyclops scutifer, Sars. 



Not having identified this and the following species it will be 

 best to quote the descriptions. 



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

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

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

 rangular! obtecta esse videtur. Seginentum 1-mum abdominale ad basin valde dilata- 

 tum latitudine quam admarginem posteriorem duplo majore. Rami eaudaies segmen- 

 tesantecedentibusduobus junctis parum longiores, introrsum clliati, setis apicaiibus 

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

 aiticulatge, reflexge segmentum 2-dum corporis superantes setis plurumque longis obsi- 

 t?e. 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 articulo basali parum minor extrorsum sparsim pilosus in- 

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

 abdomen magna ex parte obtegentes. Longit. circit. 13^ mm. 



Sp. 13. Cyclops abyssorum, Sars. 



C. strenuo et scutifero sat afQnis. Cephalothorax ovatus antice ob<;use truncatus, seg- 

 mentis parum ad latera extantibus. Rami eaudaies longi et tenues satisque divergen- 

 tes, longitudinem segmentorumantecedentium 3 superantes, setis apicaiibus longioribus 

 intermediarum interiore duplam longitudinem furc?e superante, exteriore quam ilia 

 parum breviore. Antennse l-mi paris l7-articulatae longa? et fere rectse distiucte posticl 



