RErORT UPON TWO COLLECTIONS OF MYRIOPODA, ]o5 



Pyrgodesnius, gen. nov. 



(PL ii, figs. 1, lb.) 

 Allied to Cryptodcsnuis. 



Head covered by an expansion of tbe first tergite. 

 Keels rising below the middle of the sides of the somites and 

 depressed. 



Each somite bearing a large upstanding projection or keel in the 

 middle of its dorsal surface. 



Pores minute, occurring on the 5th, 7th, 9th, 10th, 12th, 13th 

 15th — 19th segments, situated on the upper surface of a special 

 tubercle which projects from the posterior half of the lateral margin 

 of the keels. 



Pyrgodesnms obscurus, sp. n. 

 Colour (in alcohol); somites of a uniform dull brown colour; 

 labrum, antennae, and legs testaceous. 



Head tubercular above, labral region smooth but punctured and 

 hairy, produced, its sides being sub-parallel, its angles rounded. 

 Antennce close together, of moderate length, the second segment long, 

 the fifth the longest and the thickest, the sixth and seventh very 

 small, forming together a conical termination to the appendage. 



Bod,y granular and subtubercular throughout ; 1st tergite with its 

 anterior border carinate and evenly convex from side to side, as wide 

 as the second segment, bearing on its upper surface a very large, erect, 

 wide, tubercular prominence, the upper surface of which is shallowly 

 excavated ; the rest of the segments with keels depressed, oblique, i. e., 

 sloping backwards and upwards, with anterior and posterior mar- 

 gins sub-parallel, the angles squared, and the lateral margin quadri- 

 lobate, those of the 2nd, 3rd and 4th segments straight, the rest 

 projecting more and more bacli wards towards the posterior end, those 

 of the 19th small and not produced posteriorly so far as end of the 

 20th, the keels of the 2nd with margins a little thicker than those of 

 the rest, but of the same level ; the median dorsal crests or prominences 

 thicker at the apex than at the base, those at the anterior end of the 

 body directed forwards, and those at the posterior end backwards, 

 those in the posterior three-quarters of the body marked on the sum- 

 mit with a longitudinal groove, the two sides of which are bilobate ; 

 at the anterior end of the body the groove becomes deeper and deeper. 



