November io, 



•^] 



NATURE 



27 



Continental mycologists have now for some time 

 accepted the genera of the Agaricini as defined by 

 Fries, with the exception of the large genus Agaricus, 

 which Fries himself subdivided into numerous smaller 

 groups as subgenera ; but they have elevated all these 

 smaller groups to the rank of genera, and placed them 

 upon an equality with the other veritable genera of 

 Agaricini. Against this metamorphosis we feel bound 

 to contend, on the ground that the distinctions, although 

 sufficient for the subdivision of a genus, are not of generic 

 value, and that the genera so constituted are unneces- 

 sary, and of unequal value, with the old genera beside 

 which they are placed. For instance, Amanitopsis differs 

 only from Amanitce in the absence of a ring ; and 

 Aimellaria differs only from Panceolus in the presence 

 of a ring. Let any one of practice and experience com- 

 pare these pseudo-genera with Coprinus, Cantharelitts, 

 or Schizophyllum, and judge of what we say. For the 

 first time these pseudo-genera now find a place in a 

 British flora, and, although not of overwhelming import- 

 ance, we cannot permit them to pass without protest. 



Spore measurements are a recent addition to the 

 diagnoses of Hymenomyceies, and, although we contend 

 that they should be employed with caution and dis- 

 crimination, it is very satisfactory that so much attention 

 should have been given to them in this work. Not only 

 does the spore vary in size in a given species in different 

 seasons, but at different periods in the same year. This 

 is certainly true in some species which have been tested, 

 and should lead us to accept spore measurements as 

 approximate rather than absolute. 



In conclusion, we are bound to remark that this is a 

 student's book, written with a full appreciation of the 

 wants of a student, and giving all the information which 

 a student might require. In all cases, whether under 

 families, genera, or species, will be found just the details 

 which the novice will be most anxious to obtain, and, 

 although the study of these interesting but rather difficult 

 plants has been of late somewhat upon the decline, we 

 doubt not that it will revive and prosper by the aid of 

 the new " British Fungus Flora/' which will become the 

 '* text-book of British mycology," M. C. C. 



SOUTH AFRICAN SHELLS. 

 Marine Shells of South Africa : A Catalogue of all the 

 Known Species, with References to Figures in Various 

 Works, Descriptions of New Species, and Figures of 

 such as are new, little known, or hitherto unfigured. 

 By G. B. Sowerby, F.L.S., F.Z.S. Pp. 89, 5 pis. 

 [drawn by the author]. (London, 1892.) 



SINCE 1848, when Krauss published his well-known 

 work, entitled " Die Siidafrikanischen Mollusken," 

 no such list as the one before us dealing with the 

 Molluscan Fauna of this interesting and important 

 marine province has appeared. 



Krauss, who included the non-marine forms of the 

 South African region in his work, recorded 403 marine 

 species, of which 213 were considered to be peculiar to 

 the province. Many other species have been subse- 

 quently cited or described as coming from that quarter, 

 notably by E. von Martens and by our present author. 



Conchologists undoubtedly owe much to Mr. Sowerby 



^c. IS02, VOL. 47] 



for thus bringing together within the small compass of 

 this single volume, the scope and aim of which are suffi- 

 ciently indicated in its title, the scattered records of the 

 various species as known to him ; but they will equally 

 regret that the author didnot include the whole molluscan 

 fauna instead of confining himself to the testaceous forms, 

 and thereby raise the work from the level of a mere shell- 

 collector's catalogue to the rank of a work of reference of 

 real scientific value. 



Mr. Sowerby enumerates 740 species, and estimates that 

 323 of these are confined to South Africa, whilst 67 also 

 occur in European seas, and 340 have been found on other 

 coasts. Unfortunately, it is our disagreeable duty to point 

 out that this record does not include "all the known 

 species," and hence is not what the author fully intended 

 it to be, viz., " as complete as possible." An important 

 paper by Von Martens^ appears to have been over- 

 looked, for there are about thirty species named in it, in- 

 cluding some which were then new, not mentioned by 

 Mr. Sowerby. Still more remarkable is the omission of 

 the new forms described by Mr. Watson in his report 

 upon the Scaphopoda and Gastropoda, obtained during 

 the voyage of the Challenger. Davidson's " Monograph 

 of recent Brachiopoda," had it been more closely scanned, 

 would have yielded not only two species reputed to have 

 come from the Cape, but also Terebratulina Davidsoni^ 

 King, the type specimens of which, dredged on the 

 Agulhas Bank, were passed on to their describer by Mr. 

 G. B. Sowerby (the elder, we presume) in 1871. 



A number of species have been recorded by Mr. E. A. 

 Smith in an appendix to a " Report on the Marine Mol- 

 luscan Fauna of the Island of St. Helena,"- as found 

 there on what is locally known as "Sea-horn." This sub- 

 stance appears to consist of portions of a large species 

 of Tangle, probably Echlonia buccinalis, whichoccurs at 

 the Cape, whence it drifts to St. Helena. Some allusion 

 should have been made to these forms. Hints might also 

 have been gleaned from the same report, which deserves 

 to be more widely known than seemingly it is, of un- 

 doubted South African species whose names do not 

 appear in Mr. Sowerby's catalogue. 



The presence of a good index, while it obviates the 

 necessity, does not abolish the desirability of a good clas- 

 sification, and, in the present state of our knowledge 

 in matters conchological, that of Woodward's Manual is 

 hardly up to date ; it is somewhat late in the day to find 

 Dentalium still in its old place in the Gastropoda. 



Some few changes in nomenclature are made in defe- 

 rence to the law of priority, and these are set forth at the 

 end of the preface. Amongst them is Ovula, Bruguiere, 

 i^Z^ — Ovulum, Sowerby, &c., though, according to 

 some, Ovula is itself a synonym for Atnphiperas, Grono- 

 vius, 1781 ; Calliostoma is erroneously attributed to 

 Bruguiere instead of Swainson. 



There are also some oversights in the text, as, for in- 

 stance, " Columbella cerealis, Menke (Buccinu-m), Krauss 

 . . . = C. fCraussii, Sowerby," where, since Menke'sname 

 was given merely in MS., Sowerby's name stands, having 

 four years' priority over Krauss's ; Triforis is treated as 

 though of the masculine gender ; whilst the references to 

 "figures in various works " require careful checking. 



I "Ucbereinige sudafrikanische Mollusken nach der Sammlung von Dr. 

 G. Fritsch." Jahrb. Deutsch. Malak. Gesell. 1874, pp. 

 - Proc. Zool. Soc. 1890, pp. 247-317. 



19-146. 



