A NEW KOENENIA FROM TEXAS. 223 



there are two longitudinal rows of hairs on either side o£ 

 the 7nid-ventral line. In segment 3 these hairs are placed 

 farther apart and farther from the mid-ventral line, thus 

 making the longitudinal lines slightly curved. The seventh 

 and eighth segments have one seta on each side of the mid- 

 ventral line, while segments 9, 10, and 11 have one on each 

 side and one on the mid-ventral line. 



Second and Last known Stage. — The labrum is com- 

 pressed laterally, and has four pairs of hairs. Usually two 

 lateral sense-organs are present on a side, though in one case 

 only one was observed on a side. There are three cephalo- 

 thoracic hairs. The appendages have all the characteristics 

 present in the adult. On the ventral surface of the abdomen 

 the fourth, fifth, and sixth segments have each a group of 

 three hairs, to the right and left respectively of the mid- 

 ventral line, while the seventh segment has only one on a 

 side ; the eighth and eleventh segments have each three 

 setfe, one on, and one on each side of the mid-ventral line; 

 while the ninth and tenth segments have each four set^e 

 arranged at equal distances apart across the ventral surfaces. 

 It is the peculiar condition of segments 2 and 3 that makes 

 this stage of the utmost importance. These segments are 

 prolonged into appendages that give promise of becoming 

 male appendages, inasmuch as they possess papillas, a condition 

 which has been found only in the male. The second segment 

 is prolonged posteriorly and ventrally into a trowel-shaped 

 appendage, slightly notched at the edge, giving it a paired 

 appearance. There projects from its edge on either side of 

 the mid-ventral line a papilla tipped with a plumulose spine. 

 This appendage has four pairs of seta?, two pairs forming a 

 downward curving row, Avhile the two remaining pairs form 

 an irregular row near the edge. The third segment gives 

 rise to the usual pair of projections, which are supplied on 

 the outer side with a small seta. Figs. 13 and 14 of the 

 plate represent camera drawings of the front and side view 

 of these simple appendages. 



The Endosternite. — Characteristic of the Arachnida is 



