58 CONTRIBUTIONS TO CANADIAN PAI/iBONTOLOGY. 



of the Mazon Creek nodules discovered since Sir William Dawson wrote. 

 Careful search has been made for any other of those special features which 

 distinguish the Archipolypoda from recent Diplopoda, but in vain, beyond 

 the single but not unimportant point that the ventral plates, in Archiulus 

 at least, are very broad and probably almost equally extensive in lateral 

 expansion with the dorsal plates, a feature nowhere found in modern 

 Diplopoda. This is perhaps most clearly shown in the two new species of 

 Archiulus described below. 



But besides these new and old forms, all of which belong to the 

 Archiulidse, the only family of Archipolypoda heretofore known from 

 these peculiar deposits, a couple of specimens appear to indicate the pre- 

 sence of Amynilyspes, one of the Euphoberidse, but the fragments are too 

 imperfect to render the conclusion clear. A few others prove incontest- 

 ably the presence of Arachnida of the order Scorpiones. All of the 

 fragments are very imperfect ; most of them, indeed, are but mere bits of 

 the test, but we are enabled in some fashion to interpret these by the aid 

 of some of the others which show with little doubt the presence here of 

 Mazonia, a type of Carboniferous scorpions first made known from the 

 beds of Mazon Creek in Illinois, and help to indicate that its separation 

 from Eoscorpius, to which most other Carboniferous scorpions are referred, 

 was justifiable. Two species are indicated, but to only one of them, as 

 capable of somewhat definite though partial characterization, is a name 

 given. It is possible there are also others, but we may expect between 

 different parts of the body a certain — though not an unlimited — amount 

 of diversity in the surface sculpture. 



The nature of the entombment warranted no expectation of finding the 

 relatively softer integument of hexapod insects with the myriapodal 

 remains, yet Sir William Dawson in his examination of the reptilian 

 coprolites of these sigillarian stumps has extracted the fragment of a 

 facetted eye about three-quarters of a millimetre square and containing 

 from one to two hundred perfectly regular hexagonal facets arralnged in 

 regular rows and each about O'OS"™ in diameter. This could have be- 

 longed to nothing but a true insect, and in all probability is that of a 

 cockroach, since these were the prevalent insects of Carboniferous times, 

 though otherwise unknown from these deposits. This specimen has 

 already been referred to by Sir William Dawson in his Air-breathers of the 

 coal period, p. 59, and figured by him on PI. 6, fig. 56. 



Sir William Dawson has also submitted to me another fragment con- 

 taining a considerable number of delicate black acicular spines two or 

 three millimetres long, or even longer, and about O-l""" in diameter, with 

 the surface sometimes smooth, sometimes striate, but it is impossible to 

 say to what sort of creature they may have belonged, possibly to a 

 spined myriapod. 



