REPORT ON THE PELAGIC HEMIPTERA. 39 



DESCEiniON OF THE SPECIES. 



The number of species of Halohates (iu the restricted sense) alrearly described is 

 five, viz. : — 



Halobates micans, Esch. 

 „ sericeus, Esch. 

 „ jlaviventris, Esch. 

 „ streatfieldanus, Tempi. 

 ,, wiillerstorffi, Frauenf. 

 To these I am aljle to add six, namely : — 



Halohates princeps. Ilulohatcs germaniis. 



„ hayanus. „ sobrinus. 



„ proavus. „ frauenf eldanus. 



Key to the Species.i 



1 The last three joints of the antennre of equal length, . . . frauenf ddanus. 

 The last three joints not all of equal length, ..... 2 



2 Front femora more or less distinctly steel-blue in colour, .... 3 

 Front femora not blue, ........ 4 



3 Antenna with the second and third joints equally long, .... micaiis. 

 Antenn;i3 with the second joint one-fourth longer than the third joint, . icullcrstorffi,. 



4 Front tarsus with the first joint nearly twice as long as the second joint, . pi-inceps. 

 Front tarsus with the first joint never more than equal in length to the second joint, 5 



5 Antennte with second joint equal to, or a little longer than, the fourth joint, . 6 

 Antennte with the second joint distinctly shorter than the fourth join'., . . 8 



6 Front tarsus with the first joint almost as long as the second, . . flavivcntris. 

 Front tarsus with the first joint distinctly shorter than the second joint, . . 7 



7 Front tarsus with the first joint one-half shorter than the second joint; antenme 



with the second and fourth joints subequal iu length, . . . hayanns 



Front tarsus with the first joint one-third shorter than the second ; antenna; with 



the second joint rather longer than the fourth joint, . . . proavus. 



8 Front tarsus with the joints subequal in length, .... strccUfxldatms. 

 Front tarsus with the first joint shorter than the second joint, ... 9 



9 Middle tarsus with the first joint seven times longer than the second joint, . sericeus. 

 Middle tarsus with the first joint not more than five times longer than the second joint, 10 



10 Base of antennte narrowly rufous ochreous; front tarsus with first joint a little 



more than half the length of the second joint, . . . (jermanus. 



Base of antennre concolourous ; front tarsus joint about one-fourth shorter than the 



second joint, ........ sohrinv.s. 



1 The "key" must be used with caution More than one or two points have to be taken into consideration in dis- 

 criminating the more closely allied species. 



