HARRIMANIA MACULOSA 1 25 



the same habits of life, is a proposition that turns topsy-turvy 

 our morphological and phylogenetic notions to such an extent 

 that I imagine it can gain little favor among zoologists. 



Willey's arguments in support of his view are presented cate- 

 gorically in what I suppose him to regard as the order of their 

 importance in his paper on Ptychodera jiava} Stated in sub- 

 stance only, they are as follows : (1) The gonads are diffuse in 

 Ptychodera^ while they are disposed in masses with some sug- 

 gestion of metameric order in some at least of the Balanoglos- 

 sid«. (2) The gill slits of P. jlava and of some other species 

 open directly to the exterior throughout their entire length, thus 

 making the pharynx ' exposed ' as the author expresses it ; 

 whereas the gill slits open into pockets which in turn communi- 

 cate with the exterior by dorsal pores in the typical Balano- 

 glossus. (3) The respiratory region of the enteron in Ptycho- 

 dera is divided into a dorsal branchial portion, and a ventral 

 esophageal portion, while in most of the Balanoglossidce there 

 is no such division. (4) Ptychodera inhabits the littoral zone, 

 while some of the Balanoglossidas, notably Glandiceps talaboti 

 Marion, and G. abyssicola Spengel, are^deep-sea species. 



We will examine briefly these arguments one by one. The 

 diffuse arrangement of the gonads, says the author, bears all 

 the marks of an archaic type. In reply, I will quote another 

 statement from the same paper (p. 174), and parallel it, slightly 

 modified, with one of my own. In describing the gonads of 

 P. jiava, he says: "They are not in the remotest degree ar- 

 ranged one after the other, in a manner resembling a paired 

 metameric series, as they are more or less in most other Enter- 

 opneusta, but they are scattered in the most irregular way in the 

 substance of the genital pleura." My parallel to this is as fol- 

 lows, making the comparison between Am^hioxtis and Bdcllo- 

 stoma instead of \)Q.\.\NQ.^r\. Balaiioglossiis and Ptychodera: They 

 (the gonads of Bdellostoma^ are not in the remotest degree ar- 

 ranged one after the other, in a manner resembling a paired 

 metameric series, as they are in Amphwxtts, but are scattered 

 in the most irregular way in the substance of the genital fold. 

 So far as the evidence as to primitiveness is concerned, I believe 



' Willey, 1897, p. 179. 



