Apbil 23, 1897.] 



SGIENGE. 



639 



Paratype (pa7-a=beside, and typos =type). 

 — ' 'A paratype is a specimen belonging to the 

 original series, but not the type [holotype] , in 

 cases where the author has himself selected 

 a [holotype] . It should, however, be one 

 of the specimens * * * [described] in the 

 original description." The present writer 

 has removed from this definition of Thomas, 

 the words ' mentioned or enumerated ' and 

 substituted ' described.' Specimens merely 

 mentioned or enumerated add no characters 

 to the description of a species. Lists of 

 specimens giving measurements, however, 

 do add to the knowledge of a species, and 

 are to be regarded as type material, either 

 as paratype, cotype or hypotype, as the case 

 may be. 



A paratype may be subsequently selected 

 as a holotype when it proves to be a new 

 species and is not the species to which it 

 was originally referred. 



Plastotype (plastos = formed or moulded, 

 and typos = type) . — Anj'^ artificial specimen 

 moulded directly from a primary type. 

 There are many specimens of this kind in 

 existence, cast directly from fossils, and 

 these are often quite as good as the 

 originals. No models, however, can be in- 

 cluded, since they are not cast from type 

 material. Artificial casts made from sup- 

 plementary material will become plasto- 

 types if a specimen from which the repro- 

 duction was made is subsequently used for 

 the founding of a new species. 



In this connection it may be well to give 

 a name to artificial casts made from sup- 

 plementary types, since some have a very 

 decided value. For instance, many arti- 

 ficial casts are in museums of one of the 

 supplementary types of the trilobite Isote- 

 lus gigas, the only one preserving the 

 ventral limbs. For such the term hypoplasto- 

 type may be useful. 



In paleontology fossils are sometimes 

 described and illustrated from artificial 

 casts or squeezes made from natural rock 



cavities from which the fossils have been 

 leached. Such plastotypes are not to be re- 

 garded as type material. The natural 

 moulds from which they are made, how- 

 ever, should always be so considered. 



TYPICAL MATERIAL. 



Mr. Thomas has also proposed the terms 

 ' topotype ' and ' metatype.' The material 

 to which these terms are applied has not 

 served in publication, but simply refers to 

 typical material, either derived from the 

 type locality (topotype) or derived from 

 the type locality and identified by the au- 

 thor of a new species (metatype). 



These were defined as follows : Topo- 

 type. — 'A specimen simply collected at the 

 exact locality where the original type was 

 obtained.' Metatype. — 'A specimen re- 

 ceived from the original locality after the 

 description has been published, but deter- 

 mined as belonging to his own species by 

 the original describer himself.' 



Genotype (genos = race, and typos =type). 

 — Genotype applies to any typical material 

 of the type species of a genus. The ma- 

 terial, however, should be, if possible, from 

 the original locality of the species, or a geno- 

 type should also be a topotype or metatype. 

 Therefore there may be as many genotypes 

 of Lingula as there are museums having 

 characteristic specimens of Lingula ana- 

 tina. 



MARKING OF TYPE MATERIAL. 



All type material should be plainly and 

 permanently marked to distinguish it from 

 other specimens. If this is carefully done, 

 much doubt wUl be removed for subsequent 

 students. When such material is large, as 

 birds and mammals, a small highly colored 

 card or a piece of plaia zinc may be at- 

 tached, upon which should be printed or 

 stamped the proper term indicating the 

 kind of type and the museum catalogue 

 number. In paleontology it is the custom 

 to glue small colored tickets upon the type 



