GENEEA UEOTIIOE AND ITEOTHOIDES. 27 



SUMMARY AND INDEX. 



The history of the genus may be shown in brief by the following list : — 



1852. Urothoe rostratus, Dana : since called Phoxocephalus rostratus 3, 4 



1852. Urothoe irrostratus, Dana 4, 10 



1853. Effidia pulchella, Costa : since called Urothoe pulchella 4,11 



1856. Gammarus elegans, Bate : „ „ Urothoe elegans 4,5,9,13 



1857. Sulcator marinus, Bate : „ „ Urothoe niarinus 5, 16 



1860. Urothoe norvegica, Boeck 6,7,9,21 



1862. Urothoe bairdii, Bate : since called Urothoe marinus 7 



1862. Urothoe brevicornis, Bate 7, 10, 23 



1869. Urothoe marinus, Bate, ? var. pectinatus, Grube 8 



1874. Urothoe, species, S. I. Smith : since called Harpinia, species 4 



1879. Urothoe abbreviata, G. O. Sars 3, 9 



1880. Urothoe pinguis, Haswell : since called Harpinia (?) pinguis 4 



1888. Urothoe poucheti, Chevreux 9, 25 



1888. Urothoe lachne'essa, Stebbing : since called Urothoides lachmessa 4, 26 



The genus Urothoe is therefore at present composed of the following eight species :• — 



Urothoe abbreviata, Sars. Urothoe marinus, Bate. 

 „ brevicornis, Bate. „ norvegica, Boeck. 



„ elegans, Bate. ,, poucheti, Chevreux. 



„ irrostratus, Dana. „ pulchella (Costa). 



Should any reader object to finding some of the specific names masculine and others 

 feminine, he is respectfully reminded that among the specimens examined some were 

 males and others females. 



Of the eight species enumerated, it must be observed that they are more remarkable 

 for their likeness to one another than for any difierences that can be discerned. The 

 magnitude of the eyes and the structure of the lower antennse vary greatly with the age 

 and sex of the animal, the most constant feature being that the lower antennae in the 

 female have a two-jointed flagellum. Among the details that appear to prevail 

 throughout the genus may be noticed the vast number of gland-cells over all parts 

 of the body, the transparent caps to the tips of all the fingers, a pecuHar spine-row on 

 the wrist of the first gnathopods, and the long plumose setae on the third, fourth, and 

 fifth joints of the third perseopods, on the first joint of the fourth perseopods, and on 

 the second segment of the pleon. The species for the most part are to be distinguished 

 from one another only by groups of small diff'erences. Among these, however, a single 

 feature may here and there make itself moderately conspicuous : thus, only Urothoe 

 abbreviata, Sars, is said to be blind ; only Urothoe elegans, Sp. Bate, is described as 



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