1864.] IN THE MUSEUMS OF HOLLAND AND BELGIUM, 391 
Nasal bones short and broad (fig. 2). Orbital processes of frontals 
moderately long, and widening considerably at their outer extremity, 
directed nearly horizontally outwards. First five cervical vertebree 
ouly ankylosed(?). Baleen-plates moderately long, and broad at 
the base. 
Type species, £. australis (Desm.). Probably several other 
species, including Balena biscayensis, Eschr. ; but these are not yet 
well determined *. 
2. Balenopteride. The head less than one-fourth of the total 
length of the body. A dorsal fin. Skin of the under surface of the 
throat and chest provided with numerous parallel longitudinal fur- 
rows. The bones of the cranium very slightly arched. The rostrum 
broad at the base, gradually tapering, depressed. ‘The orbital pro- 
cesses of the frontal moderately prolonged, broad, and flat on the 
upper surface. ‘Tympanic bones elongated, ovoid. The coronoid 
process of the lower jaw more or less developed. Baleen-plates short. 
Cervical vertebree usually all free. Hand narrow and tetradactylous. 
This family may be divided into two minor groups or subfamilies, 
the Megapterine (genus Kyphobalena, Eschricht), or Humpbacked 
Whales, and the Balenopterine (genus Pterobalena, Eschricht), or 
Fin- Whales. 
(1.) Megapterine. Dorsal fin low, obtuse. Orbital process of 
frontal much narrowed externally. Scapula high and narrow; acro- 
mion and coracoid process absent or rudimentary. Metacarpus and 
phalanges greatly elongated. 
This division contains, as far as is known at present, but one 
genus—Megaptera, Gray, characterized, in addition to the above, by 
a total number of vertebree amounting to 53, and 14 pairs of ribs. 
Coronoid process of lower jaw low, obtuse. Nasal bones narrow, 
pointed at both ends, rising to a sharp ridge in the middle line, and 
deeply hollowed at the sides (fig. 3). 
Type species, M. longimana (Rudolphi). 
(2.) Balenopterine. Dorsal fin faleate. Orbital process of frontal 
nearly as broad at the outer extremity as the base, or somewhat nar- 
rowed. Scapula low, broad, with along acromion and coracoid pro- 
cess. Metacarpus and phalanges of moderate dimensions. 
_ Van Beneden (“ Faune Littorale de Belgique,’”’ Acad. Roy. Belg. 
vol. xxxii. 1860) has recognized the distinctive characters of three 
species belonging to this group, which he calls Péerobalena communis, 
P. gigas,and P. minor. Dr. Gray (Proc. Zool. Soc., May 24th, 1864) 
constitutes these three species as the types of distinct genera, which 
he has named Physalus, Sibbaldius+, and Balenoptera; he also 
* In a valuable monograph (‘Om Nordhyalen,’ Copenhagen, 1861), lately 
published in the Danish language, by Eschricht and Reimhardt, and about to be 
translated into English under the auspices of the Ray Society, it is conclusively 
proved that the habitat of the Balena mysticetus is, and always has been, exclu- 
sively confined to the Polar Seas, and that it has therefore no claim to a place in 
the European fauna. The Right Whales of the North Atlantic, formerly chased 
by the Basque whalers, belonged to this section of the family. 
+ [hope my kind friend Dr. Gray will excuse me, if I venture thus to mo- 
dify the generic name “ Sidbaldus,” originally proposed by him. 
