13(5 MUK.ENID.TE. 



Enchelynassa bleeken, Kaup, Apod. p. 72, fig. 55, rc(juircs re- 

 examination before it can be admitted into the sj'stem, us well as 

 the Holocetitrum found in the stomach of the typical specimen, and 

 said to be H. pwictatissimum from the Pacific. There are some 

 points in Dr. Kaup's description which render it not improbable 

 that this fish is identical with or closely allied to Enchelycore. Dr. 

 Bleeker refers Enchelynassa simply to the synonymy of Oymnothorax 

 (Murceiia). 



APPENDIX TO THE MUll^NID^. 



Under the name of LEPTOCEpnALiDiE, or HELMicninYiDiE, fishes 

 have been comprised which, of small size, show a very low organi- 

 zation. They are narrow, elongate, more or less band-shaped, pel- 

 lucid in a fresh state, but assuming a white colour when presei-ved in 

 spirits, resembling a tapeworm, being quite as soft and flexible. 

 We are indebted to Kolliker for a better knowledge of their internal 

 structure *. The skeleton is entirely cartilaginous, or slight os- 

 sifications are only now and then visible, especially towards the end 

 of the vertebral column. The latter is replaced by a chorda dorsalis, 

 which is frequently divided intu numerous segments. Now and then 

 traces of neural arches are more or less conspicuous. The anterior 

 end of the chorda passes into tlie cartilaginous base of the skull, the 

 connexion not being by means of joint and ligaments. Haemal 

 arches are found on the caudal portion. Eibs none. The skull, like 

 the vertebral column, is nearly entirely cartilaginous. The sphenoid, 

 frontal, and jaw-bones are the first which may be distinguished, and 

 the mandible has generally ossifications. 



The muscles are generally not attached to the chorda, which is 

 surrounded by a thick gelatinous mass, separating the lateral sets of 

 muscles from each other. These muscles are attached to the external 

 integTimcnt, each forming a thin flat angular band, the angle being 

 di recti 'd forwards. However, specimens are frequently found in 

 which the muscles arc more developed, evidently at the expense of 

 the gelatinous matter, whicli is diminished in quantity. They are 

 attached to the chorda ; and the entire fish has a more cylindrical 

 form of the body ^ Hehnichthys). 



The nervous, circulatory, and respiratoiy organs are well deve- 

 loped. In those with a subcylindrical body the blood is red ; in 

 those with a flat body the blood-corpuscles show but rarely a faint 

 coloration. There arc four branchial arches ; and T'durus has 

 pscudobranchia). The gill-openings are more or less narrow. The 

 nostrils are double on each side, and the posterior is close to the 

 eye. 



The stomach has a large blind sac, and in Lfptocejyhaivs two 

 li.ural oicca. The intestine is straight, running close to the abdo- 

 niiuul lu'ofilc, with a small appendix directed forward, mid a larger 



'^ SifbuM Li. Kollikor. Zi'itsi'lir. iv. IS.C'. p olid. 



