MYRIAPODS OF XOVA SCOTIA. 933 



The body is cylindrical, of uniform width throughout the principal part and tapering a 

 little at either end ; none of the specimens, however, are sufficiently well preserved to as- 

 certain in what degree or over how great an extent the body tapers ; one specimen, which 

 shows the posterior three or four segments quite clearly, tapers from 1.95 ""■ to 1.5 ""• 

 in breadth in a distance of 1.125 """■; another fragment occurring in the middle of the 

 body is 18 °™" in length and of uniform breadth throughout. It is of course impossible 

 to determine of how many segments the body was composed, but the largest fragments 

 number twenty-seven and thirty segments, respectively, and the body was probably fm'- 

 nished with at least forty or fifty ; the breadth of the body varies from 2.25 ""• to 

 3.5 ""■, and generally averages about 2.75 ™™- ; at the posterior extremity, however, it 

 measm-es only 1.15 """■ The segments of the body are a httle convex, and measm'e fi'om 

 .7 °™' to more than 1 ™"- m length, averaging .87 "^', the length bemg to the breadth 

 as 1 to 3.441. The surface is smooth, and both the anterior and posterior borders appear to 

 be shghtly incrassated. 



The fi'ustra are quadrangular in shape, extend regularly across the segments and are 

 always more than twice, and often more than thrice, as long as broad ; in segments which 

 measure from .7 ™"- to 1.05 """■ in length, the frustra vary in length from .2125 """• to 

 .45 °""-, and average .29 '°™-, the breadth being to their length (on an average) as 

 1 to 3.043 ; they are so arranged down the sides of the segments that the upper edge of 

 each is always a httle higher than the lower edge of the next frustrum above ; except in 

 partaldng of the convexity of the segment, they are flat. 



A single specimen seems to show a slight circular depression in the centre of one of the 

 frustra, which occurs about half way up the sides of the segment ; it resembles and is 

 found in the place of the lateral pores.-^ There are two pairs of legs to each segment ; 

 they arise in close proximity, and apparently not from the middle of the segment, but 

 from the middle of its anterior half (possibly its posterior half — which, cannot be deter- 

 mined fi-om tlie imperfect nature of the fi'agments) ; they are very long and slender and 

 of nearly equal breadth throughout, tapering at the tip ; they vary, probably in different 

 parts of the body, from .6 °™- to 1.45 "™- in length,^ and the largest are .075 """■ broad: 

 they are apparently composed of five joints ; of these the terminal is the longest ; the first 

 and second are equal and next in length, and the foiu'th is the smallest of all.^ 



Xylobius similis sp. nov. 



The form of this animal does not seem to differ much fi'om that of X. sigillarice Daws. 

 In one or two specimens, which show some of the terminal segments, the extremities are 

 a little smaller than the middle of the body, the diameter diminishmg near the head, in a 

 distance of about 11 """-, from 5.5 """• to 4 '""• ; the Mnder end tapers from 3.5 '""■■, 

 at a distance of 3 °™'- fi'om the extremity, to 2.75 °™- at the extremity itself. The 

 number of seg-ments on the fragments vary fr'om twenty-seven to at least forty, and in 

 one specimen apparently to sixty, whUe in none of them are all the segments preserved. 



^Foramina repugnatoria o{ ^a.ga.. ^This statement concerning the joints is doubtful, being 



^The length of the legs in this and all subsequent measure- based on a single instance, not clearly defined. 



ments, refers to the distance to ■which they extend beyond 



the crushed body. 



ICEMOIBS BOST. BOO. NAT. HIST. VOL. II. 55 



