STATE GEOLOGIST. 143 



Sp. 1. Liiimocalanus niacrunis, Sais. 



A species similar to L. macrurus has been found in lake Michigan, 

 and probably occurs also in this state in lake Superior. We can 

 do no better than quote Sars' description. 



"Corpus gracile et angustatum. Cephalothorax supi'a visus elongato ovatus, latitu- 

 dine maxima in medio sita antice et postice aeqiialiter atteauatus. Caput annulum 

 unicum prsebens, a latere visum parte antica altiore et coavexa sinu distincto a poster- 

 iore disjuncta, margine antico oblique descendente. Segmentum ultimum thoracis par- 

 vum neque ad latera extans in femina et mare simile. Abdomen sub-cyliadricum tlior- 

 ace loDgius. Bami caudales valde elongati et angustati tertium longitudinis abdominis 

 partem superantes, supra et ad latera spinulis vel pilis brevibus obsiti, intus ciliati, 

 setis 5 majoribus uniarticulatis et ciliatis, quarum 2-da ab interiore numerata omnium 

 longissima ceterseque extus graduatim longitundine decrescentes, exteriore ceteris 

 minore absque apice sat remota ; seta adest prseterea alia intus adflxa ut in generibus 

 antecedentibus tenuissima et simplex. Frons a latere visa obtuse acuminata appendic- 

 ibus tentaculiformibus duabus perbrevibus instructa. Antennae 1 -mi paris reflexje seg- 

 mentum penullimum abdominis minime attingentes, articulo ultimo setis 5, quarum 

 posteriores 2 longissimse, instructo, articulis anteceaentibus 3 setEe simili postice ver- 

 gente prteditis ; dextra maris articulatione inter articulum l8-mum et 19-mum geniculans. 

 Antennarum 2-di paris ramus exterior interiore et longior et latior, 7-articulatus, ai'ti- 

 culo 2-do omnium maximo, sequentibus 4 minimis junctis articulo ultimo brevioribus 

 setisque longissimisinstructis. Mandibulse ad extreraitatem inferiorem in rtentes ex- 

 euntes 9, quorum exteriores 2 ceteris majores, interiores 2 tenues et setiferes sunt ; pal- 

 pus longus et angustatus 3-articulatus, articulis ultimis 2 brevissimis, ramo exteriore, 

 vel appendice branchiale, parvo. Maxillae l-mi paris eadern fere structura ac in Diap- 

 tomo. Maxillae 2-di paris validissinife 8-arliculatEe, articulis ultimis 5 in ungues exeun- 

 tibus longissimos et fortissimos margine altero sparsim pilosos, ad apicem falcatum 

 vero nudos vel aculeis persubtile et dense obsitos ; 3-tii paris [Maxillipedes] valde elon- 

 gatae et angustatae antice vergentes articulis 7 setis pleurumque longis praeditis compo- 

 sitae. Pedes omnes biramosi natatorii, ultimo pari in mare bi-articu!atus in pede dex- 

 tro et sinistro dissimilis, articulo ultimo in illo brevi etrobusto ad apicem quasi trun- 

 ycato dentibusque 3 parvis et obtusis armato intus vero in aculeum magnum et validum 

 excurrente, in hoc valde elongato extus et ad apicem aculeato intus vero nudo. Oculus 

 UDicus propius marginem inferiorem capitis situs. Animal quamquam pellucidissimus 

 et fere omniuo hyalinum, facile taraen accumulatione in thorace sat magna liquoris 

 oleosi l«te fulvo-rubide colorati se prodit. Longir. circit. 2\i mm." 



FAMILY CYCLOPID^. 



Contains five genera, viz: ThorelUa, Cyclops, Oithona, Lopho- 

 pJiorus and Cyclopina; passing, by the genera. Misophria and Pseu- 

 do-cyclops, into the Calanidce or marine copepods. The affinities of 

 these little known genera need further study, as they are very in- 

 teresting, the question being still open in how far the cyclopoid 

 forms are altered by adaptation to saline habitat, if such an adapta- 

 tion takes place at all. 



Cephalothorax ovate and usually much more robust than the 

 abdomen; anterior antennas seldom longer than the cephalothorax, 

 those of the male alike on both sides and modified for the purpose 

 of clasping; posterior antennse unbranched (i. e. palpus wanting); 



