330 PORPITA. 



^Aji exactly parallel case, that of Coluber, has recently been examined by 

 Dr. L. Stejneger (:07). Both Coluber and Medusa are Linnaean genera, each 

 including widely diverse species now referred to various genera and even families, 

 and of course Linne did not indicate a type species for either. From each, 

 the early reviewers, Lamarck in the case of Medusa, removed certain species, 

 and left certain other species in the original genus, without, however, designating 

 any species as types. As Stejneger points out, according to the International 

 code of nomenclature, subsequent designation of the types for the Linnaean 

 genera must be made from among the species left in them by the first reviewers. 

 Although the first reviewer did not designate a particular species as type, still 

 the fact that he allowed certain species to remain in the original genus shows 

 that it is one of these which is to be considered as typifying it. Such being the 

 case, whatever species may, or might have been selected as type of the genus 

 Medusa, it can not be M. porpita; and therefore there is no justification for 

 discarding Porpita in favor of Medusa. 



The question, how many species of Porpita deserve recognition, is difficult 

 to answer because of the brief and unsatisfactory nature of the descriptions 

 upon which many of the proposed names rest. It is important however, to reach 

 a sound conclusion in this regard. Porpita is such a tj-pical pelagic surface 

 animal that an accurate knowledge of the occurrence of its species would be of 

 much service to students of the geographic distribution of pelagic organisms in 

 general. For that reason I attempt a review of the subject, though it can not 

 be final without additional knowledge of the Pacific, and especially of the Indian 

 Ocean forms. 



In treating the Atlantic and Mediterranean forms there is every reason to 

 follow Chun ('97b) in uniting all described forms under the name P. umbella 

 (O. F. Miiller, 1776). 



We must next consider the species which have been recorded from the 

 Pacific. The oldest notice is by Lesson ('26) who figured and named P. 

 chrysocoma from near New Guinea, and P. pacifica from off the coast of Peru, 

 in the atlas of the zoological results of the voyage of "La Coquille." In the 

 interim between the appearance of these figures and his very meagre and alto- 

 gether insufficient description (1830), Eschscholtz ('29) gave his account of the 

 Tropical Pacific P. ramifera and P. coerulea. The first of these was based on 

 very young specimens ("Eine halbe Linie" in diameter). There is nothing in 

 the description to differentiate them specifically from any of the various recorded 

 races of Porpita. P. coerulea, however, was based on larger specimens, up to 



