302 PROCEEDINGS OF THE ACADEMY OF [May, 



from Paraleptijnia and Ceratiscus the new genus differs in the spinose 

 head, also from the former in the more abbreviate antennse and from 

 the latter in the narrower head, more abbreviate metatarsi and 

 non-lobate limbs. 



Head bispinose ; greatest width of the head less than the length of 

 the same; antennae short, composed of fifteen joints, the proximal 

 longer than broad, the next subquadrate, the third subequal to the 

 first in length, the fourth transverse, the remainder longitudinal and 

 tapering, the fifth and sixth less longitudinal than the succeeding ones, 

 all depressed. Median segment longitudinal, subequal to the head 

 in length. Cerci of female terete; subgenital plate of female greatly 

 elongate, lanceolate, compressed. Limbs non-lobate; tarsi abbreviate, 

 in no case a fourth the tibial length ; metatarsi of the cephalic limbs 

 slightly more than half the length of the tarsi, of the other 'limbs a 

 half or less than a half the length of the same. 



Type: X. missionum n, sp. 



Xiphophasma missionum n. sp. 



Type: 9 ; Misiones, Argentina. December 18, 1910. (No. 7.) 

 (P. Jorgensen.) [Acad. Nat. Sci. Phila., type No. 5,214.] 



Size large; form very elongate. Head with the greatest width 

 contained one and one-half times in the length of the same; paired 

 horns placed between the caudal portions of the eyes, slightly diver- 

 gent and inclined slightly cephalad; eyes not 

 at all prominent, in fact slightly recessed, in 

 outline nearly circular; antennse as described 



^. „ v-Li. under the genus, their length about equal to 



Fig. 8. — Xiphophasma n i , , ^ ^ ^T i- -, 



missionum n. gen. that of the head and half of the pronotum; 



and sp. Lateral out- occipital margin with three moderately dis- 



Ime of head of tvpe. ... . 



( X 2.) ~ tmct indentations, the whole head narrowing 



caudad. Pronotum with its length subequal 



to that of the head caudad of the eyes, longitudinal, the median 



width very slightly greater than half of the length ; the lateral margins 



sinuate dorsad of the insertion of the coxae. Mesonotum about five 



and a half times the pronotal length, subequal in width in the greater 



portion of its length, faint traces of a median carina present. Meta- 



notum (including median segment) nearly four-fifths the mesonotal 



length, similar in structure to the mesonotum; medium segment 



not separated from the metanotum proper by a transverse sulcus. 



Abdomen with segments one to seven longitudinal, progressively 



increasing in length distad, eighth segment longitudinal, but little 



