Mr. W. Yarrell on some Species of the Genus Syngnathus. 83 



ciation at Newcastle last autumn^ Mr. Wallace, of the Isle of 

 Man, gave me two specimens of S. ccquoreus ; I therefore now 

 possessed four examples of this rare fish, all dried, and all ap- 

 parently females, there being no appearance of the hemispheric 

 depressions which usually distinguish the males. On care- 

 fully opening these four we found that two of them were 

 males and two females, and contrary to M. Fries's experience, 

 the males, in this instance, were the two largest of the four. 

 Supposing the disappearance of the hemispheric cells in the 

 dried males of the ophidial pipe-fish to be the consequence of 

 desiccation, I tried the experiment of drying a male specimen 

 of >S^. Ophidion, Bloch, which, when taken out of diluted spirit 

 of wine, bore the usual half circular depressions, and I found 

 that these depressions became less conspicuous in three or 

 four hours, and were lost in the sculpture of the abdominal 

 plates when the specimen became quite dry. 



The best specific distinction between S. cequoreus, Linn, and 

 S, Ophidion, Bloch, as it has been generally called, appears to be 

 in the situation of the anal aperture, which marks the division 

 between the body and tail in fishes. In the largest male of 

 S. cequoreus, measured on this occasion, the body was 9f 

 inches, the tail 10^ ; in the second, the body was 9:,- inches, 

 the tail 9^. In the largest male specimen of S, Ophidion that 

 was measured, the body was 6 inches, the tail 8 inches ; in 

 another the body was 4 inches, the tail 6. 1 admit that there 

 is considerable resemblance in the form and sculpture of the 

 plates, but in this country S. cequoreus is as rare as the >S^. 

 Ophidion of Bloch is common : males and females of both 

 exist, as has been shown, and I have not yet met with any 

 specimens, which by forming an intermediate series, would 

 bring these two fishes together. I have hitherto referred to 

 this second ophidial pipe-fish by the name of S. Ophidion, al- 

 though M. Fries is, I believe, perfectly correct in stating that 

 the Ophidion of Jenyns and Yarrell, identical with the Ophi- 

 dion of Bloch, tab. 91. figure 3. as quoted by both in their 

 synonyms, is not the true Ophidion of Artedi and Linnaeus ; 

 but let us inquire a little further. In this country we are in 

 the habit of referring to the works of Swedish naturalists, 

 considering them good authorities for the Linnaean species. 



