392 



SCIENCE. 



[N. S. Vol. XI. No. 271. 



fossils, regarding liis Hydnoceras as a ceplia- 

 lopod. In the same year Vanuxem described 

 another form, Uphantsenia, as a plant, and this 

 was the current interpretation for all the 

 Dictyospongidee until 1881, when Whitfield, 

 from Lower Carbonic material, determined that 

 they were the remains of sponges. Nearly all 

 these fossils are found in sandstone, while the 

 living Euplectellas are commonly anchored on 

 muddy bottoms. 



The present monograph begins with ' Gen- 

 eral Observations on the Sponges.' These are 

 followed by sections on the aflBnities, structure 

 of the skeleton, preservation, and occurrence, 

 of the Dictyospongidee . A detailed review of 

 the bibliography, in which there are 42 entries, 

 is next given, and then come a classification 

 and the descriptions of genera and species. 

 The family Dictyospongidas is here divided into 

 seven sub-families, all new. These are : Dicty- 

 oapongiinse, Thysanodictyinie, Calathospovgiinse, 

 Physospongiinee, Hyphanixniise, Sallodictyince, 

 and Aglithodictyinss. Of new genera there are 

 Dictyospongia, Hydriodictya, Prismodictya, Oon- 

 glospongia, Botryodictya, Tylodietya, Helicodictya, 

 Bhabdosispongia, Ceratodictya, Lehedictya, Thy- 

 sanodictya, Arystidiatya, Aclceodictya Gripho- 

 dictya, ' Galathospongia, Clepsydrospongia, Boem- 

 erispongia, Hallodictya und A glithodicty a. Masto- 

 dictya is another new genus, but is undefined. 

 Sphserodictya is proposed to replace in part 

 Teganium Raufif", which seems to include heter- 

 ogeneous material. Cyalhophycus is considered 

 objectionable, because the name indicates a 

 plant. On this ground Dawson changed it to 

 Cyathospongia, a name used earlier by Hall. In 

 this volume, the latter term is replaced by 

 Cyathodictya. It is a question whether anything 

 is gained by these changes {Cyathophycus to 

 Cyathodictya, and Uphantsenia to Hyphantsenia). 



Hydnocerag Conrad was proposed for ' an 

 extravagant type of orthoceran cephaloped.' 

 This, however, never came into use and is here 

 revived ' not because it was founded on a mis- 

 conception, but because it perpetuates one ' 

 {sic). On the other hand Dictyophyton was in- 

 troduced by Hall in 1863, ' at the request of 

 Mr. Conrad * * * to replace the term Hydno- 

 ceras.'' The genotype is D. newherryi, which 

 was also accepted for Thamnodictya in 1884, 



Under the rules of nomenclature such changes 

 are not usually permissible, but since Dictyo- 

 phyton ' tends to perpetuate the old and erro- 

 neous conception of the algous nature of these 

 fossils ' the name may be allowed. 



The paleontology of New York serves as the 

 highest expression of the work on American 

 invertebrates, not only from a scientific stand- 

 point, but also in artistic appearance. This 

 volume on the sponges continues the previous 

 standard, in spite of the fact that the preserva- 

 tion of the extinct glass sponges does not per- 

 mit of much detailed elaboration. From an 

 artistic standpoint, the present monograph is 

 equalled by no other, not even by the elaborate 

 ' Systeme Silurien du Centre de la Boheme ' of 

 Barrande. Professor Hall long ago recognized 

 the accurate and artistic draughtsmanship of 

 Mr. George B. Simpson and the ability of Mr. 

 Philip Ast in lithographic work. Few can appre- 

 ciate the skill and patience of the latter in over- 

 coming technical difiiculties. For 50 years New 

 York has nobly supported her workers in pure 

 science, and paleontologists look to that Com- 

 monwealth and to Dr. Clarke for a continuance 

 of the splendid series of volumes on the pale- 

 ontology of the State. 



Chables Schuchert. 



books received. 



77(6 Iniernational Geography, by seventy authors. 

 Edited by Hugh Eobeet Mill. New York, D. 

 Appleton & Co. 1900. Pp. xx + 1088. $3.50. 



Jenaer Glas und seine Verwendung in Wissenschaft und 

 Technik. H. Hovestadt. Jena, Fischer. 1900. 

 Pp. xil + 429. 9 Mark. 



The Criminal. AUGUST Drahms, with an introduc- 

 tion by Cesaee Lombeoso. New York and Lon- 

 don. The Macmillan Company. 1900. Pp. 

 xiv+402. $2.00. 



Municipal Government. BiED S. CoLEE. New York, 

 D. Appleton & Co. 1900. Pp. ix + 200. 



Man and his Ancestor. Charles Morris. Now 

 York and Loudon. The Btaemillan Co. Pp. 

 vi + 238. $1.25. 



SCIENTIFIC JOURNALS AND ARTICLES. 



The January number (Vol. I., No. 1) of the 



Transactions of the American Mathematical 



Society contains the following articles : ' Conies 



and cubics connected with a plane cubic by 



