Cviil PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [May 1 896, 



off the "West Indies, is represented by two almost identical forms, 

 described by Prof. Dr. Anton Fritsch, namely, JStenocheles esocinus, 

 Fr., and Stenocheles jparvulus, Fr., both from the Chalk of Bohemia. 

 Ischnodactylus incequidens, Pelseneer, from the Uppermost Chalk of 

 Limburg, belongs apparently to the same group of Crustacea. 



Is Thaumastocheles Zaleucus a deep-water survival from the Chalk- 

 sea of Europe, and did its area extend to the West Indies ? 



Dr. Paul Pelseneer has figured and described a cephalothorax of 

 Galathea (named G. Ubaghsi) from the Maestrichtien or Upper 

 Chalk of Limburg, and I have received from Miss Caroline Birley 

 another example of the same genus from the Danien Upper Chalk 

 of Faxoe. 



Brachyura (Crabs). — Standing between the long-tailed Lobsters 

 (Macrura) and the short-tailed Crabs (Brachyura) is an anomalous 

 group of forms, of considerable extent among living Podophthalma, 

 fortunately, but few of which are met with as fossils. These -were 

 formerly elevated into the rank of a distinct tribe, the ' Anomura/ 

 but a careful consideration soon reveals the fact that this name, like 

 some still in use in other zoological groups, is but the confession of 

 our ignorance as to the exact position of the individuals relegated to 

 such scientific dust-bins. 



G. 0. Sars has made an earnest effort to clear up the relations of 

 some of these Anomura, and, from a study of their larval stages, 

 he is led to refer to the Macrura the following forms, namely : — 

 Lithodes, Eujpagurus, Anapagurus, Munidopsis, Galathea, Munida, 

 and Porcellana. Of these, Porcellana and Lithodes heretofore had 

 been placed on the side of the Brachyura, but, tested by their larval 

 stages, they are really Macrura. On the other hand, the Dromidae, 

 Homolidae, Raninidae, and Dorippidaa belong to the anomalous 

 forms of Brachyura. Such * borderland' genera are among the 

 familiar difficulties known to every zoologist in the study of any 

 natural order, even when fossil forms are not, as in the present 

 instance, taken into consideration. 



In this anomalous group we are frequently enabled to penetrate 

 the veil which Mature too often spreads over her workings, and 

 to discover the secret of the transformation in appearance which 

 many of these adult Crustacea assume, and detect how it has been 

 brought about. 



Thus we find that all those forms which constantly hide them- 

 selves in burrows, or in shells of dead mollusks, living sponges, 

 sea-anemones, and other like hiding-places, become in time quite 



