Archky. — Occurrence of Craterostigmus tasmanianus. 319 



Art. XXII. — The Occurrence in New Zealand oj Craterostigmus tasmani- 

 anus Pocock (Chilopoda). 



By Gilbert Archey, M.A., Assistant Curator, Canterbury Museum. 



[Read before the Philosophical Institute of Canterbury, 7th June, 1916; received by 

 Editors, 30th December., 1916; issued separately, 24th August, 1917 '.] 



The genus Craterostigmus lias hitherto been known from only two speci- 

 mens, collected on the summit of Mount Rumney, Tasmania, in 1892, by 

 Mr. G. M. Thomson, of Dunedin. It was described in 1902 by Pocock,* 

 who pointed out its great importance, in that it occupies an intermediate 

 position between the Scolopendromorpha and the Lithobiomorpha. The 

 former have 21 body-segments, each with tergum, sternum, and a pair of 

 legs ; the latter have only 15 of such segments. Craterostigmus, however, 

 has 21 terga, but only 15 sterna and 15 pairs of legs. Certain other charac- 

 ters show the relationship of the genus to one or other of the groups Litho- 

 biomorpha, Scolopendromorpha, and Geophilomorpha ; and in one or two 

 characters, particularly in the presence of a bivalved sclerite at the posterior 

 end, bearing the genito-anal aperture, the genus is unique. It therefore 

 takes rank equally with the above-mentioned groups, and is the sole repre- 

 sentative of the order Craterostigmomorpha. For full particulars of these 

 details reference must be made to Pocock's important memoir cited above. 



I am now able to record the species from the South Island of New 

 Zealand, where it has been found in several localities. 



A description of the species, mainly taken from Pocock's paper, is given 

 here for the convenience of New Zealand workers who may not have access 

 to the Quarterly Journal of the Microscopical Society. 



Order CRATEROSTIGMOMORPHA Pocock, 1902. 

 Genus Craterostigmus Pocock, 1902. 



Craterostigmus tasmanianus Pocock, 1902. R. I. Pocock, Quart. Journ. 

 Micr. Soc, vol. 45, p. 423, pi. 23, 1902. 



Colour (in spirit) greenish-yellow, head and toxicognaths dark reddish- 

 brown. Integument sparsely hairy and punctured. (Pocock describes the 

 colour as yellowish-brown : this may be due to the use of a different 

 preservative.) 



Cephalite (fig. 1) parallel-sided, its posterior border convexly rounded ; 

 frontal area with its sides converging between the eyes and the base of the 

 antennae. Eyes some distance behind the antennae ; frontal sulcus pro- 

 jecting posteriorly between the eyes, with strongly convex backward curva- 

 ture. Antennae with 18 segments, the segments hirsute, especially towards 

 the distal end of the appendage, subcylmdrical, longer than wide. Prae- 

 coxal processes of toxicognaths (fig. 2) long, armed apically and externally 

 with 7 teeth, inner side of femur and femoral processes armed with about 

 5 teeth, inner side of the trochanter armed with 1, tooth just behind 

 the suture marking the line of union of trochanter and femur. Basal 

 plate with posterior angles rounded. Terga without longitudinal grooves, 

 with posterior border straight, posterior angles rounded, and unthickened 



* R. I. Pocock, Quart. Journ. Micr. Soc, vol. 45. pp. 417—18, pi. 23, 1902. 



