458 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxix. 



back Into it. The young grow rapidl}'^ and become sexuall}" mature 

 in one year. 



From observations made in 1S81, and prior thereto, Ryder thinks 

 that the eggs of the pipefishes are impregnated at the time of ti'ans- 

 fer, and that the period of development is from twelve to fourteen 

 days. He avers that in the young of S. pecManus {S. fuscum) there 

 is developed a low, continuous fin-fold which, however, is never so 

 prominent as in other Teleosts — for example, Gadu.s. However, on the 

 contrary, in 1884, Ryder writes that "there is no continuous hn-fold 

 developed at all in Siphostomaov Hippocampus.'''' In his earlier paper 

 (1881), he says that the operculum is from the beginning tied down, 

 leaving only a spiracular-like opening, thus contradicting Rathke 

 (1837). 



McMurrich (1883), from work on S. fuscum at Beaufort, aiBrmsthat 

 the young when born are 10 to 11 nnu. long and have the yolk-sac com- 

 pletely absorbed. I have young of this species nearly ready to hatch, 

 but possessed of a ver}' large yolk-sac — one too large to be absorbed 

 before hatching. The hatched young of S. jloridse^ 11.5 mm. long, 

 possess the remnants of the yolk-sac inclosed within the abdominal 

 walls. This is not visible in the whole mounts, but is shown in sec- 

 tions. Two young (species unknown) from the "tow," one 15 mm. 

 the other 18.6 mm. long, show a considerable remnant of the 3^olk 

 inside the body walls. They are the largest young in my possession, 

 the next oldest being 90 mm. long, and (males at an}^ rate) sexually 

 mature. 



McMurrich further says: " In young stages an anal is present, 

 which, however, does not pass be3^ond the stage in which fibrillation 

 begins, but aborts, and is entirely wanting in the adult." Larvae of 

 this species 5.5 mm. long and with a great yolk-sac (some days away 

 from hatching) possess the rudiments of the anal, and adult examples 

 in my possession have very small but perfectly distinct anals. Kupffer 

 (1868) says of a European Syngnathus (species not given) that the 

 young on hatching (whether from shell or pouch is not stated) have a 

 relatively large yolk-sac. Just here it may be of interest to say 

 that the newly hatched young of //. kudsonius have no yolk-sac 

 visible in the whole mounts. Sections, however, show a small rem- 

 nant within the body wall. 



Ryder in 1886 speaks of an "exceptionally discontinuous fin-fold" 

 in Siphostoma^ from which dorsal, caudal, and anal fins are developed, 

 and says that T. H. Bean showed him a Siphostoma with a secondary 

 anal fin, which could only be explained by development from such a 

 fin-fold. He figures a horaocercal tail for a 3"Oung pipefish. In the 

 young of Siphostoma Jloridse up to a length of 18.5 mm. (m^^ latest 

 stage) I find what seems to be the remnants of a continuous fin-fold, 

 especiall}' plain on the ventral surface. This shows both in the whole 



