296 JOURNAI, OF CONCHOLOGY, VOL. I3, NO. lO, APRIL, I912. 



As to the priority craze, that has now proceeded so far as to land 

 scientific nomenclature into a veritable morass, and it will require 

 some authoritative pronouncement to bring matters back to their 

 proper proportions. The question then arises, who is that authority 

 to be ? Das Tierreich is a painstaking and really good work so far 

 as it has gone, but, like everything else German, it is too German, 

 and not calculated to meet with such general acceptance (even if one 

 could see the end of it) as the more impartial plan of the Inter- 

 national Zoological Congress. If the latter is carried out on common- 

 sense and consistent lines, avoiding anything like mere scientific 

 pedantry, it would go far to reconcile all conflicting interests for the 

 sake of scientific harmony and peace, wiiich, after all, is what 99 out 

 of every 100 scientists require. 



To return to the Pleurotomidas, Clathurella or Defraticia is one of 

 the best-defined groups of this family, and yet that is not without its 

 transitional forms, one of which, for instance, described by Boog 

 AVatson first as Fleuroto/na perparva, and subsequently as 

 Clathurella (?) perparva, " is classed under the Clathurella only 

 provisionally, in consequence of the departure of the embryonic 

 whorls from the typical sculpture."^ Dejrancia has been superseded 

 by some authors for Clathurella on the ground of its being pre- 

 occupied for the Polyzoa, and there appears to be no doubt that, 

 according to the strict law of priority, Clathurella holds the field. 

 Its bibliography is a little obscured, but the Rev. R. Boog Watson 

 puts it shortly in this way—" Millett's earlier name (1826) of 

 Defrancia, which has been largely adopted, is preoccupied by Bronn 

 (1825) for a genus of Polyzoa, which had indeed been previously 

 named Pelagia by Lamoureux (182 1), but that name having been 

 preoccupied by Peron (1809) for a genus of the Acalephas, the 

 Defrancia of Bronn must come into use [for the Polyzoa]. The 

 Defrajuia of Millet must, therefore, unfortunately be dropped [for 

 the MoUusca], and Carpenter's name Clathurella adopted."^ 



The embryo of Clathurella is conical, tumid, and exquisitely 

 reticulated transversely. The embryos of Rissoa Jeffreys! and Ovula 

 patula are somewhat similarly sculptured. A very large number of 

 new species of tiie Pleurotomidce (nearly 100) were procured in the 

 Porcupine Expedition, and are still undescribed, a few of which were 

 also dredged in the Challenger and other expeditions. Mr. Sykes has 

 described about eight of these,^ but the great bulk, consisting of dead, 

 imperfect, or embryonic specimens, has been left unnoticed, though 

 the latter especially are easily and distinctly separable, exhibiting as 



1 Challenger Gastropoda, p. 361, pi. xxii., fig. 8. 



2 ChalU\nger Gastropoda, p. 348. 



3 Moll. Porcupine Exp., Supp. Notes, Part III., Proc. Malac. Soc, 1906, vol. vii. 



