20 Mr. C. T. Recrau on the 



the paiasplienoid, the breadtli of tlie ethmoid, no doubt 

 correhited with the stren<^th of tlie prsemaxilhuies, and the 

 veiy small fontanel between the supra-occipital and parietal?. 



Family 4. Electrophoridae *. 



This family also contains only one sjiccies, the electric eel, 

 Electropho7'us electricus {Gymnottts electricus), differing from 

 the preceding in the characters of specialization enumerated 

 in the synopsis. 



Division 3. C Y P K i N i F R m e s. 



Body deep or moderately elongate ; dorsal and caudal fins 

 well developed ; pelvic fins usually present ; no adi[)0se tin. 

 Mouth toothless, typically protractile. Opisthotic small or 

 absent ; posterior temporal fossa absent or variously deve- 

 loped, when present with a single posterior aperture. Lower 

 pharyngeals typically falciform, not opposed to the toothless 

 Tipper pharyngeals, but to paired posterior processes of the 

 basioccipital, vrhicli may unite below the aorta. Hyopalatine 

 and opercular bones all jiresent ; palatine movably articulated 

 with niesopterygoid. Post-temporal simple. 



Sagemelil (Morph. Jahrb. xvii. 1891, pp. 4:89-504, 

 pis. xxviii. & xxix.) has given a detailed account of the cranial 

 osteology of this group. The skeleton is very similar to that 

 of the Cliaraciformes, but there are some important differences. 



In all ihe Cypriiiiformes the orbitosphenoid joins the 

 ulisphenoids behind, the laternl ethmoids in front, the frontals 

 above, and the parasphenoid below. The palatine ends 

 l)ehind in a convex head which fits a concavity of the meso- 

 ])terygoid; internally it articulates with the "" scj)to-max- 

 illaries," which are usually ossified and firmly united to the 

 vomer, appearing as antero-latcral apophyses of that bone, 

 but may remain as cartilages intervening between the vomer 

 and palatine. The "septo-maxillary " and palatine articu- 

 late anteriorly with the maxillary, either directly or through 

 the intervention of one or two pairs of " submaxillary " or 

 *' pre-palatine " cartilages (Catostomidaj) or bones (Cobitidse, 

 Homnloptorida.'), which are more or less reduced in the 

 Cypriiiida'. 



The pra.Mnaxillaries have ascending pedicels which are 

 attached to the extremity of a movable "rostral^' bone; 

 this is articulated with the vomer and is vertical when the 



* On the eloolric organ, sec Sacb^, ' Uutorsucbungen am Zitteraal,' 



1881. 



