136 MFR.ENIB^. 



Enchelynassa hJeeleri, Knup, Apod. p. 72, fig. .55, requires re- 

 examination before it can be admitted into the system, as well as 

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

 said to be //. i^unctatissimnm 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 EnchcJycore. Dr. 

 Bleeker refers Enchelynassa simply to the synonymy of Oymnothorax 

 {Murcena). 



APPENDIX TO THE MUll^NID^. 



Under the name of LEPTocEPHALiDiE, or HELMicnTHYiciE, fishes 

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

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

 lucid in a fresh state, biit assuming a white colour when preserved in 

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

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

 stiTJCture *. 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, 

 Avhich is frequently divided into numerous segments. Now and then 

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

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

 connexion not being by means of joint and ligaments. Ha3mal 

 arches are found on the caudal portion, llibs none. The skidl, like 

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

 frontal, and jaw-bones are the first which maybe 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 

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

 directed forwards. However, specimens are frequently found in 

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

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

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

 form of the body {Helmichthys). 



The nervous, circulatory, and respiratorj' 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 are four branchial arches ; and Tilurus has 

 pseudobranchia3. The gill-openings arc 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 Leptoc€2>haIus two 

 lateral cajca. The intestine is straight, running close to the abdo- 

 minal profile, with a small appendix directed forward, and a larger 



'* SicboLl u. Ki'llikrT, Zeitsuhr. iv. 18,32, p 'MO. 



