574 ivAR trAgArdh 



to have a very wide distribution, tiie tropics when once investigated will reveal 

 a great number of new forms which will make it necessary for us to remodel 

 our conceptions of the system. 



The present genus is a beautiful example of the difficulties which will 

 confront us when exploring the acarofauna of the tropics. 



If we accept the key of the Oribatei published by Sellnick (1929). we 

 arrive through Aptyctima, Apterogasterina to Brachypylina which are charac- 

 terized through the tibia being generally much longer than the genu and more 

 or less clavate. Of the nine families belonging to this group all except Tegeo- 

 cranidcB may be eliminated. Amongst the genera of this family there are, 

 however, some which in several respects resemble Cerocepheus, especially Tri- 

 tegeus Berl., which in my opinion is the only one hitherto known which has any 

 affinity to Cerocepheus. In both the anterolateral angles of the dorsal shield 

 project as triangular projection and in both the dorsal side is covered by a 

 secretion. The lamellae of Cerocepheus, on the other hand, resemble more those 

 of Cepheus. 



Cerocepheus is, however, a very highly specialized form, specialized in 

 two directions which may, or may not, be correlated. The cuticle of the whole 

 body is covered by a layer of waxy secretion which is thicker than the animal 

 itself. This explains the flattened dorsal side of the hysterosoma, the peculiar 

 long, flexible hairs, viz. interlamellar and 5 pairs of dorsal hairs of the hystero- 

 soma, which are embedded in the wax and aid in its adhering to the dorsal 

 surface. The great size of the pseudostigmata is another feature obviously 

 connected with the presence of a thick covering of wax, because these organs 

 would be quite concealed, and unable to function, if they were of the ordinary 

 size. Finally the exceedingly short and feeble legs are very likely also a feature 

 correlated with the wax cover. Evidently Cerocepheus is a very slow creature 

 which is sufficiently protected by the covering of wax and does not need to 

 run quickly in order to escape its enemies. It is in this connection of great 

 interest to recall that the claws were brooken ofi" on all legs. It is open to 

 conjecture whether they were really all brooken off because they were too weak, 

 or were bitten off by some enemy. 



Not less remarkable is the specialisation of the mouthparts, with the ex- 

 ceptionally long mandibles with their small chela. As far as we know, more 

 or less similar mandibles are to be found independently in several families or 

 genera, as f. i. Pelops, Serrarius, Metrioppia and Suctobelba, which are not 

 related. In Cerotegeus they resemble more those of the Uropodida; than 

 anything else. It may be that further investigations will reveal in the tropics 

 the presence of other related genera with similar mandibles. Then it will per- 

 haps be necessary to make Cerocepheus the type of a new family, but for the 

 time being I prefer to refer it to the Tegeocranidce. 



Eutegaeus Berl. 



In 1908 Michael described a new species, Oribata Bostocki from New 

 Zealand. Although M. admitted that the species was a very remarkable 

 one he did not create any new genus for it. If he had lived to the pre- 



