Jordan and Evermann. Fishes of North America. 



Family III. MYXINID^E. 

 (THE HAGFISHES.) 



Body eel-shaped, covered by a thin skin, which is easily detached. 

 Along the lower side, for nearly the whole length of the animal, are 2 

 rows of mucous glands, each with an external opening, yielding an abun- 

 dance of mucus which renders these animals excessively slimy. No eyes. 

 Hrain small, of the normal fish type. Skull little developed, cartilaginous : 

 the flexible notochord inclosed in its sheath, and extending from the base 

 of the skull to the end of the tail, representing the spinal column. Mouth 

 round, suctorial, without lips, with a pair of barbels on each side. Nostril 

 single, large, on the median line above, and at the very front of the head, 

 provided with 2 pairs of barbels. Teeth strong, a single median one on 

 the roof of the mouth, and 2 rows on each side of the tongue, which is 

 a powerful organ, with a strong fibrous tendon moving in a muscular 

 sheath. Alimentary canal a simple nearly straight tube, without spiral 

 valve ; gill sacs placed on each side of the ossophagus, lying directly 

 against its outer walls. The water passes into them by a small pore open- 

 ing directly from the oesophagus into each sac. It is then passed out by 

 a duct, which continues backward along the outer walls of the sacs to 

 the abdominal wall at the end of the last sac, where all the ducts from one 

 side unite in one, and the water is emptied at the branchial opening on 

 each side of the median line. In close connection with the branchial 

 opening 011 the left side there is a third opening that leads by a very short 

 duct to the oesophagus, and hence into the branchial sacs, at the times 

 when the supply of water through the mouth is cut off by the head being 

 buried in the flesh of the animal on which it feeds. Ovary single, on the 

 right side. No oviducts ; the mature eggs falling into the abdominal cavity 

 and excluded through the peritoneal opening at the side of the vent. Eggs 

 with a horny case, and threads for adhesion. Parasitic animals, burrow- 

 ing into the bodies of fishes, and found in the cold seas. 



Two species are usually recognized Myxine olivacea, Lace*pede (=aus- 

 tralis, Jenyns), from the coasts of Patagonia, and Myxine glutinosa. 

 (Myxinidce, genus Myxine, Giiuther, vui, 510-511.) 



4. MYXINE, Linnaeus. 



.1//.i-/H*% LINNAEUS, Systema Naturae, Ed. x, 1758, 650, (glutinosa). 

 Gastrobnmchns, BLOCK, Ichth., xii, 51, ta>. 413, 1797, (coccus). 

 Mnr:nil>lHiift, LAcfcpKDE, Hist. Nat. Poiss., v, 647, 1803, (olivacea). 

 AHOJMHS, KAFINFSQTK, Anal, de la Nature, 493, 1815, (olivacea). 



Characters of the genus included above. (An old name, from /*va, 



slime). 



6. MYXINE GLUTINOSA,* Linnaeus. 



(HAQFISH; BORER.) 



Head 3$ to 4 in total length ; tail 6| to 10; lingual teeth 8 to 11 in each 

 row. Bluish above, whitish below. North Atlantic on both coasts, 



* " Myxini' is generally or always in its young stage a male, while at a more advanced stage 

 it becomes transformed into a female. It seems to be an animal which in sexual respects is in a 

 transition stage, from what and to what it is hard to say. It seems to be seeking, without yet 

 reaching that mude of reproduction which is most profitable for it in the struggle for existence. " 

 Fridljof Namen. 



