622 Subclass Dipneusti, or Lung-fishes 



peat. Their galleries run horizontally and are usually two feet 

 long by eight inches wide. After the eggs are laid the male 

 remains curled up in the nest with them. In the spawning 

 season an elaborate brush is developed in connection with the 

 ventral fins. 



Protopterus, a second genus, is found in the rivers of Africa, 

 where three species, P. annectens, P. dolloi, and P. athiopiciis, 

 are now known. 



The genus has five gill-clefts, instead of four as in Lepidosiren. 

 It retains its external gills rather longer than the latter, and 

 its limbs are better developed. The habits of Protopterus are 

 essentially like those of Lepidosiren, and the two types have 

 developed along parallel lines doubtless from a common ancestry. 

 No fossil Lepidosirenidce are known. 



FiG. 393. Protopterus dolloi Boulenger. Congo River. Family Lepidosirenidce. 



(Alter Boulenger.) 



Just as the last page of this volume passes through the 

 press, there has appeared a bold and striking memoir on the 

 "Phylogeny of the Teleostomi," by Mr. C. Tate Regan of the 

 British Museum of Natural History. In this paper Mr. Regan 

 takes the view that the Chondrostean Ganoids (Palaoniscum, 

 Chondrosteus, Polyodon, Psephurus, etc.) are the most primi- 

 tive of the Teleostomous fishes; that the Crossopterygii, the 

 Dipneusti, the Placodermi, and the Teleostei (as well as the 

 higher vertebrates) are descended from these; that the Coc- 

 costeida (Arthrodires) are the most generalized of the Placo- 

 derms, the Osteostraci and most of the other forms called Ostra- 

 cophores (Antiarcha, Anaspidd) being allied to the Arthro- 

 dires, and to be included with them among the Placodermi; that 

 the cephalic appendage of Pterichthyodes, etc., is really a pectoral 

 fin ; that the Heterostraci (Lanarkia, Pteraspis, etc.) are not 

 Ostracophores or Placoderms at all, but mailed primitive sharks, 



