Reviews — Fritsc/i's Fauna of the Gas-coal. 37 



legs, the form of the head, the compounrl eyes, the ocelli, the 

 nntennfB, and the jaws. Nineteen plates are likewise devoted to the 

 illustration of the various forms of these curious M^'riopods, giving 

 full detail of their structure and ornamentation. One form of King- 

 crab is alsodescribed underthenaraeof Pro^mnZMsPFooJtpardt (Fritsch). 

 The shales in which these remains abound are pyritous, and the 

 fossils in them very rapidly perish. In ordei', therefore, to rescue 

 the evidence of these organisms from destruction, the author has hit 

 upon the idea of making electrotypes of all the important specimens, 

 which thus become 2)ermanent records in the Prague Museum. This 

 is no novel process, however, as Jules Marcou introduced the same 

 method of electrotyping the Trilobites of Canada forty years ago. 



One cannot fail to he impressed by the great antiquity of these curious 

 forms of many-jointed terrestrial air-breathers, which even at this 

 early geological period enjoyed so wide a geographical distribution 

 over the globe. Their primitive character and simple elongated 

 forms, with sometimes cylindrical, sometimes flattened body, present 

 the greatest resemblance to the Annelids in the serial similarity of 

 the rings of the body and in their mode of locomotion. 



The genera described by Dr. Fritsch embrace Acantherpestes, 



3 species ; jEnphoberia, 2 species ; Isojniiis, 3 species ; Plenrojulus, 

 G species; Anthracojalus, 1 species; Pylojnhis (Xylobias), 4 s^^ecies ; 

 Acroglomeris, 2 species ; Archiscudderia, o species ; Glomeropsis, 



4 species ; Ilemiphoberia, 1 species ; Piirki/uia, 1 species ; Hetero- 

 vorhoefia, 1 species ; and Sandlneria, 1 species. 



The Arachnoidea also ajDpear to claim a very early place among 

 the air-breathers in geological time. No scorpions are here figured 

 by Dr. Fritsch, although some of the earliest examples of this 

 remarkable type were obtained by Count Sternberg from Bohemia. 

 The spiders are represented by the genera Hemiphrynus, 2 species ; 

 JPvomygale, 3 species ; Arthrolycosa, 3 species ; and Pyritaranea, 

 1 species. On plate cliii is figured a remarkable example of 

 Arthrolycosa jjrolifera, a female having a cocoon of well-developed 

 young attached to its body. Enlarged figures of some of the 

 embryo spiders are given. One is at a loss to understand how the 

 small shells known as Spirogh/phus vorax happen to be found 

 attached to the body of a spider (Promygale rotundatn, pi. cliii, 

 fig. 4) ; these small discoidal spiral shells were formerly considered 

 as the cases of marine, or at least aquatic, Annelids. They were 

 probably forms of some kind of parasitic tube-dweller, perhaps 

 terrestrial. 



We cannot help expressing regret that the draughtsman who 

 prepared the plates had not possessed a more delicate and artistic 

 perception of the objects he has delineated. They might have been 

 made so much more beautiful by being less coarse and heavy ia 

 execution, and the expenditure in colouring seems to us to be after 

 all of doubtful value compared with extreme accuracy of minute 

 detail and correct drawing of the outlines. 



All praise is due to Dr. Fritsch for the earnest labour he has 

 bestowed for so many years in bringing out his great work on the 



