OSTEOLOGY ETC., OF SYNGNATHUS PEOKIAXUS. 623 



On the Osteology and Development of Syng- 

 nathus Peckianus (Storer). 



Bj 



J. Play fair SlclWurricb, II. A,, 



Professor ia the Ontario Agricultural College, Guelph, Canada. 



With Plates XLII and XLIII. 



It is now some time since I began the study of Syngna- 

 thus, recognising the fact that little, if anything^ had been 

 done towards elucidating many points in the anatomy and de- 

 velopment of the grotesque group of the Lophobranchs. Other 

 matters have prevented as rapid work, and as close application 

 to the subject in hand, as would have been wished for, and 

 even now the work is exceedingly incomplete. Nevertheless 

 it has seemed to me to be wise to publish the observations as 

 far as completed, inasmuch as I have been able to throw some 

 light on certain points, and to correct some mistakes made by 

 authors who have preceded me. 



The material for study was obtained at Beaufort, N.C., 

 where it was quite abundant among the seaweed near the 

 shore. The presence of the brood-pouch on the under surface 

 of the postabdominal region of the male renders the collection 

 of young stages comparatively easy, but the intermediate stages 

 between the newly hatched young and the adult were less 

 easily obtainable, and I have been unable to bridge over this 

 gap in my observations. The material under observation may 

 be divided into five stages, the relative characters of which may 

 be described as follows : 



