Mr. J. Lubbock on two new species of Calanidse. 163 



above with unnecessary minuteness, as it was the very closeness 

 of the agreement which struck me, and which brought before me 

 in quite a new Hght the text which says, that " the very hairs of 

 our head are all numbered/^ Who can help adoring that om- 

 nipotent power whose influence we perceive in everything around 

 us, and which extends to things which we should have thought 

 almost too insignificant for His notice ! 



Geographical Distribution. 



The species belonging to the genus Labidocera have hitherto 

 only been found in the Atlantic Ocean and in the southern 

 hemisphere. L. Darwinii and Patagoniensis were collected by 

 Mr. Darwin off the coast of Patagonia, Lat. 38° 40' S. Ascend- 

 ing towards the Equator, at L. 18° to 22° S., and from 2° ^0/ W. 

 to 4° E., we find their places supplied by L. magna, Pontella 

 Bah'dii, and Monops grandis ; further north again these yield to 

 A. Patersonii, which is found from the north of Ireland 54° N. 

 to 60° N., and from 6° to 25° 45' W. Probably every part of 

 the Atlantic is inhabited by one or two species of this group. 

 They are all inhabitants of the open sea, and as they swim in 

 great shoals must furnish abundant food for fishes, Medusse, and 

 other marine animals. All these species form, though belonging 

 to different genera, a group characterized by having the right 

 anterior antenna of the male swollen and provided with dentated 

 plates, and, as far as we know at present, the Atlantic Ocean is 

 the only part of the world in which this group occurs. Among 

 the large number of Calanida obtained by Dana in the Pacific, 

 and among those figured by Gaimard in the " Voyage en Scan- 

 dinavie," the antennse are only geniculated, as in the common 

 Cyclops vulgaris. There are probably many species of this group 

 as yet un described, but I do not know of any others at present 

 existing in our collections. 



Classification. 



The presence or absence of superior and inferior eyes, and the 

 structure of the right antenna of the male and the fifth pair of 

 legs, whether prehensile or not, have hitherto been considered as 

 generic characters, and upon them the classification of the family 

 is founded. The eyes present the most useful characters ; and 

 though the antennse and fifth pair of legs, being simple in the 

 females, are not so convenient, yet as the species generally occur 

 in shoals, in which the two sexes are found together, it will in 

 most cases be found tolerably easy to make out the names. It 

 may be doubted, however, whether these are really of generic 

 value ; for instance, Monops grandis and A. Patersonii, both of 



