HEMIPTBRA— HETEROPTEEA-COEEID.E. 419 



Tahlc of the genera of fossil Alijdinw. 



Hind femora spined beneath 1. Cacalydm. 



Hind femora unarmed. 



Posterior lateral angles of thorax produced as a spine 2. Ci/damus. 



Posterior lateral angles of tborax not produced. 



Thorax scarcely narrower at apex tlian at base 3. Parodarmistus. 



Thorax distinctly tapering from base to apex. 



First joint of antenna3 no longer than the head. 



Head distinctly longer than the thorax ; first joint of antennie (at least in Protenor) 

 as long as the head. 

 Body slender; thorax tapering gently, of about equal length aud breadth. 



4. Protenor. 



Body robust; thorax tapering rapidly, twice as broad as long 5. Tenor. 



Head and thorax suboqiial in length ; first joint of autenuio shorter than the head. 



Second joint of autennie much longer than either of the others 6. Elirocoris. 



Second, third, and fourth joints of anteuua) subequal 7. Bliepocoris. 



First joint of antenuie much longer than the head 8. Orthriocoriaa. 



1. CACALYDUS gen. nov. {uaxo?, Alydus, nom. gen.). 



Nearly allied to Alydus but differing from it in the structure of the 

 antennfe, which are distinctly shorter than the body; the first joint about 

 as long as the head, the other three subequal, the terminal joint incrassated 

 gently, but no longer or scarcely longer than the second and third. The 

 head is more than half as broad as the thorax, subquadrate or subrotund, of 

 about equal length and breadth; the eyes not very strongly prominent. 

 The body is elongate, subequal, the thorax tapering forward to a greater or 

 less degree. The legs moderately stout, the hind femora strongly incras- 

 sated, and on the outer half of their inferior surface armed more or less dis- 

 tinctly with spines. These, unfortunately, are not shown in the drawings 

 of either of the species. 



Table of the species of Cacalydiis. 



Species of large size (more than eleven millimeters long); head scarcely constricted behind the eyes. 



1. ('. lapsus. 

 Species of moderate size (less than nine millimeters long); head strongly constricted behind the eyes. 



2. C. exsiirpatus. 



1. Cacalydus lapsus. 



PI. 25, Fig. 12. 



A large species, of which unfortunately but a single specimen is at 

 hand. Intraocular space of the head scarcely equaling one-half the 

 widtli of the head, the surface rather coarsely, faintly, and transversely 

 corrugate, not constricted in the least behind the eyes, so that there is no 

 neck at the junction of the head and thoi'ax. Thorax subquadrate, a little 

 broader than long, tapering but gently, the surface nearly smooth. Fore 



