No. 501] 



NOTES AND LITERATURE 



023 



pelagoes," Vol. II,- Part 2, pp. 631-680, 1903, stands first in 

 point of numbers of new forms, 5 species and 1 genus being 

 added in this, all but one coming from the island groups men- 

 tioned in the title. The exception, the type of the new genus 

 Willeyia, comes from Zanzibar. Besides the 5 full-fledged new 

 species recognized by Punnett, the 6 varieties of an old species 

 Ptychodera flara arc interesting. These are based on a statis- 

 tical study of the 222 specimens in the collections. This is the 

 first effort made to treat any of the Enteropneusta statistically, 

 and is noteworthy on that account if for no other. The author's 

 attitude toward the subject seems practical and sane. He re- 

 marks: "I am not here concerned with the question of the statis- 

 tical method as a criterion of species and varieties. My point 

 is that in the group of animals collectively designated Pt. flava 

 there are to be found different positions of organic stability, 

 and in giving to these 'a local habitation and a name' there is no 

 thought of distinguishing by statistical methods between the 

 terms race, variety and species." The only question would be 

 as to the sufficiency in number of specimens examined and the 

 structural features considered to justify all these subdivisions 

 in this particular animal, and the question is to be answered 

 only by further examination of more material. 



The next largest numerical contribution is from the Siboga 

 Expedition (Studien fiber die Enteropneusten der Siboga-expe- 

 dition, Monographic XXVI, pp. 1-126, 1907, by J. W. Spengel). 

 Three fully accredited species are here described. Worthy of 

 note, perhaps of approval, is Spengel's practise, which is spe- 

 cially illustrated in this report, when dealing with certain forms 

 which he finds to differ somewhat from any already recorded 

 species, but yet not sufficiently to warrant giving them full 

 specific rank on the basis of the small evidence at hand. To 

 these he attaches a "provisional" specific name. Three such 

 names are used in this report. They usually designate speci- 

 mens from a particular geographic locality. 



Spengel appears to be ever dubious about the specific identity 

 of specimens of Enteropneusta occurring in widely separated 

 places. Thus in his "Neue Beitr&ge zur Kenntniss der Enter- 

 opneusten," I and II (Zoolog. Jahrb., 1903 and 1904), he ex- 

 amines in great detail specimens of Ptychodera flava Eschsch. 

 from Laysan, and concludes that they differ sufficiently from 

 those described by Willey from New Caledonia, to deserve being 



