The "Order" Meridogastra {Anthracomarti) 141 



point out any character indicating a generic difterence between Poliochera and Cryptostemvm. 

 Nevertheless, we would not on that account propose to cancel the genus Poliochera and regard 

 the name as synonymous with CryptoHtemma; because it is quite possible that the animal 

 figured by Scudder may possess generic characters different from those of Gryptostemma, which 

 are not visible on his figure, but which may be ascertained in the future, perhaps by means 

 of better preserved specimens. Besides, it does not seem probable to us that one and the same 

 genus (according to the modern acceptation of this term) has existed both in the period of the 

 Coal-formation and now. Whilst therefore Poliochera may be retained as a genus, though a new 

 diagnosis is at least a desideratum, the family cannot retain the name Poliocheridw, which only 

 dates from 188."), but must either bear the name Cryptostemmid;i?, which was employed by Westwood 

 as early as 1874, or that which, for linguistic reasons, we ourselves prefer, Cryptostemmatoidae. 



There remains the question whether Cryptostemmatoidaj can properly be referred to the 

 order Meridogastra (Anthracomarti). In this respect we must note first of all that the number 

 of abdominal segments is a most important character for a series of orders of recent Arachnida. 

 In the recent Cryptostemma our predecessors had discovered only four abdominal segments, to 

 which some added a segmentum anale, whereas the real number is nine. Now, if naturalists 

 have failed to discover more than one-half of the really existing segments in the firmly chitinized 

 dermoskeleton of such a rather large recent form as Cryptostemma, this seems to prove the 

 impossibility of ascertaining with any accuracy the number of abdominal segments in the great 

 majority of fossil Arachnida. In Phrynus there are twelve segments, but the first .sternite is 

 scarcely visible, and that the difficulty of counting them sometimes is great may be concluded 

 from the fact that Scudder states the number of segments in the specimen of Geraphrynus 

 carbonarius which is represented in his fig. 12, to be nine, whereas the figure plainly shows 

 eleven sternites. It will likewise in most cases be impossible to ascertain correctly the number 

 of joints in the antennae ; the structure of the limbs and of the mouth — all of which offer 

 characters of the greatest systematic importance for the definition of the orders. Finally, it is 

 doubtless, as already mentioned, owing only to a certain similarity to Trogulus in the general 

 ajjpearance, that hitherto all writers excepting Karsch have placed Cryptostemma amongst Opi- 

 liones, although differing in structure as much as possible from that order. These considerations 

 seem to jJi'ove the necessity of exercising the greatest caution both in referring fossil Arachnida 

 to orders founded on recent animals (uiile.ss the similarity between the fo.ssil and the recent 

 animal is very striking indeed) and in founding new orders on fos.sil Arachnida. If possible 

 even greater circumspection is I'equired in placing a recent animal in an order of Arachnida 

 founded on fossil remains, because this may turn out, as it has happened with Meridogastra, 

 to consist of really quite heterogeneous elements; the reference of a recent animal to such 

 an order may be tantamount to not classing it at all. 



We are of opinion that there is no possibility of proving Cryptostemmatoidae {Poliochera 

 included) to be as nearly related to any fossil form referred to the Meridogastra (Anthracomarti), 

 as to the sub-order Uropygi (the existence of which in the Coal period has indeed been demon- 

 strated with certainty long ago); and, as said above, we believe that Cryptostemmatoidae ought 

 to constitute an order apart. We have already shortly indicated our view as regards Haase's 

 proposals for classing the other elements of Meridogastra with other orders ; and we hold that 

 all those which cannot with reasonable certainty be placed in the orders founded on now 

 living Arachnida, ought to be left standing by themselves as genera (and species), of which 

 the systematic position is as yet unknown. The order Meridogastra ought therefore to disappear 



