HUNGERFORD: AQUATIC HEMIPTERA. 51 



The Nymph. 

 In the last nymphal instar the wing- pads reach to the base of the 

 abdomen. The lateral margins of the prothorax are flattened but not 

 "buckled" or constricted as in adult. The hind tarsi are single segmented. 

 Ocelli are present! In Mononyx fuscipes, Champion says the ocelli are 

 absent in the nymph. This is the usual case. 



Genus MONONYX Guer. 



So little is recorded in regard to the biology of the species that some 

 one should rear it. It is predatory, as was long ago recorded. 



Champion says that the adult has only one claw on its fore tarsi, the 

 nymph of M. fuscipes has two long' claws. The segments of the inter- 

 mediate and hind tarsi are fused into one, and the third and fourth an- 

 tennal joints are connate. The ocelli are absent. 



Habitat. "These insects live in muddy places on the banks of ponds 

 and sti'eams and are usually coated with an earthy incrustation, which 

 cannot be easily removed." 



Family OCHTERID^ Kirk. 1906. 



A. Taxonomy of the Ochterid^. 



Family Characteristics. Shore bugs with characters intermediate be- 

 tween those of Saldidm and those of Gelastocoridae. The general appear- 

 ance is also intermediate, resembling some of the Saldids, perhaps more 

 than the toad bugs. The antennse are four segmented, shorter than the 

 head, but exposed. The eyes are prominent, two ocelli present. Fore 

 femora slightly if at all fitted for grasping. Rostrum is long, like that 

 of the Saldids, reaching the hind coxse. The first and second segments 

 are short, third, very long and slender. Tarsi are given by Parshley as 

 two-segmented behind, with a question mark after the statement "front 

 and intermediate tarsi one-segmented." We have but two specimens in the 

 Snow collections at University of Kansas. The middle tarsi appear two 

 segmented under binocular. Professor Barber's drawing of his Ochterus 

 haiiski shows three segments in hind tarsi and two in each of the others. 



Historical Review. There is but one genus in the family. Ochterus 

 Latr. 1807. He suggested the name Pelogonus for this genus two years 

 later because he believed Ochterus was preoccupied. It is under the name 

 Pelogonus that Uhler mentions these insects. The genus is sufficiently 

 characterized by the family description. A more nearly complete de- 

 scription can be found in Amyot & Serville, page 407. 



KEY TO SPECIES OF OCHTERUS. 



(After Barber.) 



A. Clavus entirely yellow. O. flaviclavus Barber. 



AA. Clavus concolorous. 



B. Entire lateral pronotal margins broadly pale. 



O. hanksi Barber. 

 BB. Lateral pronotal margins, with only a pale spot anteriorly. 



O. americanus Uhl. 



