ACARINA FROM THE JUAN FERNANDEZ ISLANDS 58 1 



If we examine the diagnoses and drawings of these two species, O. cri- 

 nitus and O. longior^ we find that they differ so profoundly in some essential 

 respects, that it seems very doubtful whether they belong to the same sub- 

 genus. In 0. longior the pseudostigmatic organs are placed exceptionally far 

 forwards, whereas in O. cnnitus they are placed further backwards. In O. 

 longior the anterior margin of the hysterosoma is rounded, and the posterior 

 part of the propodosoma has no projections; furthermore the interlamellar hairs 

 are very small and inconspicuous and inserted a little in front of the pseudo- 

 stigmata, and the lamellar hairs are either absent or placed so far forwards as 

 to be rostral hairs, in which latter case the rostral hairs are either placed sub- 

 marginally and not seen or missing. In O. crinitus, on the other hand, the 

 interlamellar hairs are long and both lamellar and rostral hairs are visible, 

 placed closely together far forwards. The anterolateral angles of the hystero- 

 soma are sharp and project forwards and in the posterior part of the propodo- 

 soma there are four semicircular, depressed areas surrounded by ridges. 



In 191 3 Berlese created a new subgenus Odontocephcus (p. 95) character- 

 ized as follows: »Notogastro dentibus in margine antico, lineae mediae longi- 

 tudinali sat adpressis duobus. Margo posticus cephalothoracis dentibus duo- 

 bus, qui supradictos notogastrii attinguent. Cajtera ut in subgen. Carabodcs, 

 Typus: Tegeocranus elongatus MiCH.» 



It is quite inconceivable how Berlese came to make elovgatus the type 

 of this subgenus, because MiCHAEL, who gave an excellent description of this 

 species, accompainied as usually by beautiful drawings, does not mention nor 

 delineate any teeth on the propodo- or hysterosoma at all! 



And in order to add to this confusion BERLESE in the same paper de- 

 scribes and delineates a species Otocephetis damceoides (p. 93, fig. 66 pi. 6) which 

 has these four teeth. We can only suppose that some error has crept in 

 Berlese's paper and that in reality he intended to make O. damceoides the 

 type of the new subgenus although by an oversight he made C. elongatus 

 the type. 



The fact remains, however, that the genus includes two species which, 

 according to the modern conception of generic differences amongst the Ori- 

 batei, do not belong to the same genus. 



O. longior having been described first, this species must be considered 

 the type of the genus Otocepheus, the diagnosis of which I propose to for- 

 mulate as follows: sBody very elongated, three times as long as it is 

 wide, pseudostigmata placed far forwards, interlamellar hairs very 

 small, anterior margin of hysterosoma convex, rounded, tectppedia 

 II very large, triangular in outline from dorsal view, no true lamellae. 



This leaves O. crinitus out and as it can neither be placed in Carabodes 

 sensu stricto nor in Odontocephcus a new genus must be created, which will 

 also include the new species from Juan Fernandez. As a further investigation 

 of the tropical acarina-fauna will undoubtly yield many new forms more or less 

 related to this genus, I think it is most appropriate to defer the establish- 

 ment of a new genus until more forms have been investigated. 



Length 137.0 [jl, width 680 (jl, length of propodosoma 250 ji. 



Colour pale straw yellow, with darkbrown legs. 



