5^ 



NATURE 



\Nov. 17, 1887 



flint-gravel derived from the Chalk give evidence of a still 

 wider region once covered by its waters, but whose deposits 

 have since been removed by denudation. 



The white Chalk, whence the name " Cretaceous" was 

 taken, is almost wholly confined to the Anglo-Parisian 

 area, where the system was first studied, but the forma- 

 tion, varying in lithological characters, may be followed 

 from England into France, Belgium, Holland (Maestricht), 

 Denmark (Faxoe), south of Sweden, Hanover, Brunswick, 

 Saxony, Bavaria, Bohemia, Moravia, Switzerland, Austria, 

 and the chain of the Alps, the Mediterranean Basin, in- 

 cluding parts of Spain, south of France, Italy, Greece, 

 Asia Minor, Sicily, and North Africa. This latter is the 

 well-known " Hippurite Limestone " of the South of 

 Europe, which stretches away to Persia and the Hima- 

 layas, and extends over the greater part of the continent 

 of India. Cretaceous fossils have also been traced as far 

 south in Africa as Natal. 



The vastness of the Cretaceous system in North Ame- 

 rica far exceeds even our largest computation of its aggre- 

 gate mass in the European area, being from 11,000 to 

 13,000 feet in thickness ; whilst in our own hemisphere 

 it probably does not exceed 7000 feet as a whole. It 

 extends across the breadth of the North American con- 

 tinent, and over wide regions in South America, marked 

 by many of the characteristic fossils of the Cretaceous 

 rocks of Europe. But the evidence of contiguity to 

 land in North America demonstrated by plant and 

 animal remains far surpasses our own very limited 

 records of shore and shallow-water conditions in Cre- 

 taceous times in Europe. Nevertheless we do possess at 

 Aix-la-Chapelle, and in Saxony and Bohemia, Upper 

 Cretaceous beds containing plant remains, such as 

 leaves of Acer, Alnus, Credneria, Cunmnghamites, and 

 Salix, with Conifers akin to Sequoia and Pandanus, 

 South African, and Cape Proteacece,z.nd many Cryptogams, 

 chiefly ferns, such as Gleichenia, Lygodium, Asplenium, 

 &c. These have been dealt with elsewhere, as have also 

 the Cephalopoda (" Cephalopoden der Bohmischen Kreide- 

 formation," von Dr. Anton Fritsch ; Prague, 1872). 



The present monograph presents us with descriptions 

 and figures of seventy-two species of Crustacea obtained 

 from eight localities and well-marked beds in the Creta- 

 ceous formation of Bohemia. These are divisible into 

 Cirripedia (twenty-one species), Bivalved Entomostraca, 

 Ostracoda (twenty-one species), Decapoda-Macroura 

 (eighteen species), Decapoda-Brachyura (twelve species). 

 The Cirripedia, with one exception, all belong to the 

 stalked division (Lepadidse), or "barnacles," eleven 

 species being common to our own Chalk and Gault. In 

 these are included two varieties of <^hat most aberrant 

 genus Loricula, first described by Sowerby from the 

 English Chalk, and afterwards more fully by Charles 

 Darwin. This pedunculated genus, by a retrograde de- 

 velopment, no longer stands supported on its stalk, but 

 lies prone, attached by one side to the surface of some 

 shell, or other foreign body, its five rows of peduncular 

 imbricating scales (over 100 in number) serving to form 

 a dermal covering to the soft parts of the animal, which 

 must have been distorted in its mode of growth somewhat 

 as the flat-fishes (Pleuronectidse) are modified as the 

 result of their recumbent habits. 



A Balanus, referred to a new genus {Balanula ?), is 



supposed to represent a sessile form of Cirripede. Such 

 a form, Pyrgoma cretacea, was described from the 

 Upper Chalk of Norfolk by H. Woodward in 1868 

 (see Geol. Mag., vol. v. p. 258, pi. xiv. figs. 1-3), but 

 the "acorn-shells," Sessile Cirripedes, mostly belong to 

 the Tertiary and Recent periods, in which they attain a 

 large development all over the globe. 



The Ostracoda have been determined by Herr Joseph 

 Kafka, Dr. Fritsch's assistant, in the Museum at Prague. 

 Of the twenty species here treated of, five have been 

 previously figured and described as new by Herr Kafka 

 in the Sitzungsb. K. bohtn. Gesell. Wiss., Prag, 1885. 

 The figures and woodcuts of the old species have been 

 mostly taken from Prof, von Reuss's memoir on the 

 Microzoa in Geinitz's " Elbithalgebirge," and the new 

 species are here also figured in woodcuts, some of which 

 leave much to be desired as to " finish " of characteristic 

 features. Figs. 24 and 25 appear to belong to Macro- 

 cypris, and not to Bairdia. Fig. 26 has no relation to 

 Bairdia, but may be a Cytherella. The representation of 

 Cythere reticulata, Kf. (Fig. 32, a, b, c), has some pecu- 

 liarities which better figures perhaps would clear up. 

 Though not mentioned by Herr Kafka, ten of the 

 species are found also in the English Chalk, and the 

 others (excepting Fig. 32) have near allies in that forma- 

 tion in Western Europe. It is stated that in Bohemia 

 the Ostracoda are mostly found in the Senonian stage. 

 Only Cytheridea perforata, and four other species, come 

 from the Turonian beds of Weissenberg. 



Turning to the higher forms of Crustacea, the Decapoda 

 (crabs and lobsters), only a single species, Enoploclytia 

 leachii, Mantell, is recognized as being identical with our 

 Chalk Crustacean fauna ; but the genera Hoploparia, 

 Callianassa, Palceocorystes, Necrocarcinus, Etyus, and 

 Astacus are represented by corresponding species in the 

 two areas. Callianassa is said to be represented by six 

 species. This is a burrowing form, of which only the 

 great chelate appendages are usually found fossil, or are 

 brought up in the dredge from deep water, and it is 

 extremely doubtful, judging from the author's figures, 

 whether more than about three out of six of Fritsch's 

 species can be maintained. One Greensand species 

 occurs in Ireland, and the well-known Callianassa faujasii 

 described eighty-eight years ago from the Uppermost 

 Chalk of Maestricht. We have also a Tertiary form 

 described from the upper marine series, Hempstead, Isle 

 of Wight. All these species are very nearly related to 

 each other. 



Perhaps one of the most interesting forms described by 

 Dr. Fritsch is his Stenocheles esocinus, the long slender- 

 toothed chelae of which agree closely with those of 

 Astacus (?) zaleucus, W. Schm., a Crustacean dredged up 

 in 1000 fathoms during the Challenger Expedition near 

 St. Thomas in the West Indies. 



The present work is illustrated by ten chromolitho- 

 graphic plates and seventy-two text figures. 



This series of fine memoirs, which is being issued by 

 Dr. Fritsch from the Royal Bohemian Museum, Prague, 

 will certainly maintain the merit, and serve to enhance 

 the reputation, of that great institution, which has, quite 

 recently, been so well endowed by the magnificent bequest 

 of the late Dr. Joachim Barrande, the historian and 

 palaeontologist of the Silurian system of Bohemia. 



