22 



PROCEEDINGS OF THE NATIONAL MUSEUM. 



VOL. XXVIII. 



EEYTHR.EI'S .SPINATl'S. 



There are four genera, three of wliieli, Er)/tJi)'^iis^ AnydtH (foruierl}" 

 Actineda)^iin^ Gel'ohut^ are known from the United States. Anystis 

 and J^t'ythra'us are free and predaceous, feeding on an}' small insects 

 or acari that th(\v may come across. Tlieir movements are excessivel}' 



rapid and erratic, sometimes whirling 

 al)out in a zigzag course like a particle 

 of dust blown by the wind. In Atiystl,^ 

 the body is triangular and the palpi are 

 four-jointed. In Eryflirn'ux the body is 

 more elongate, and the palpi live-jointed. 

 Our one species of Anydtx^ A. agilis 

 IJanks, is commonly found running over 

 the leaves of herbs and shrubs in the 

 search for prey. It is red in color. I 

 have seen it feed on aphids, on small 

 caterpillars, and on the .voung larvjv of 

 the currant saw-tly. The young before 

 transformation spins a white silken web 

 on a leaf, or crevice of bark, and be- 

 neath it changes to the adult form. 



Species of KrytJir^us are known to 

 occur about houses, l)ut most of them 

 live on trees. The}" are usually red in color, but some are marked with 

 white spots and stripes. They are not very common in our country, 

 l)ut two species have been descrilied. (iel'oUd is found attached to 

 \arious reptiles, especially 

 lizards. Three species are 

 known from Europe, and 

 one, G. te.caiia^ is found on 

 Scelojyorus floi'klaiut.'< m this 

 country. 



The typical species is very 

 broad, broader than long, and 

 the coxte all close together; 

 in G. tci-ana and one Euro- 

 pean species the body is longer 

 than broad and the hind coxte 

 separated from the anterior 

 pairs. The mandibles have a 

 peculiar sti'ueture; they con- 

 sist of a stout rod with a 

 short, acute, stout spur near 

 the tip. They are supposed to 

 suck blood from the lizards; nothing is known of their earlier stages. 

 Berlese has recently changed ErytJir^us to Erythacarus^ claiming 

 that the type of Ei'ytlivivxx is a IxIiyncliolopJni.s. 



Fig. 25. — CtEKOBia texana. «, beak above; b, beak be- 

 low; r, TIP OF mandibles; (I. palpus; e, tarsus with 



f'LAWS. 



