ON PENNELLA BALAINOPTERA:. All 
also stated that Batrp referred a Pennella from a sunfish captured in Cornwall to 
P. filosa. G. M. THomson gave an account (1889) of a Pennella found on a swordfish 
(Histiophorus herscheli), which he named P. histiophori. Ramsay H. Traquarr has 
called my attention to two specimens of Pennella in the Collection of the Royal Scottish 
Museum, which he had provisionally named P. orthagorisci. Possibly they may have been 
included in the Natural History Museum of the University, which was transferred many 
years ago to the Royal Scottish Museum, but nothing definite is known of the animal 
on which they were parasitic, or when they were obtained. One specimen was deprived 
of the head and arms; the other had a head and two lateral arms, but no dorsal arm, 
and it was about 5 inches long.* 
Observations on the Lerneidee during the first quarter of the last century induced 
naturalists to consider that these parasites were not to be regarded as Worms, Molluscs, 
or Zoophytes, but that they had an affinity to the Crustacea. Their position was 
finally adjusted in 1832 by ALExanDER von NorpMaANN, who, from the young having 
the non-parasitic character of Cyclops, from the segmented structure of the male, which 
is a free swimming animal, though it may become attached to the female, and from the 
position and characters of the feet, definitely placed these curious animals amongst the 
Crustacea, in which they are now generally regarded by naturalists as forming a family 
of parasitic Copepoda. 
An important extension of our knowledge of the hosts to which different species of 
Pennella may become attached was made when it was ascertained that specimens had 
been obtained imbedded in the skin of species of whales frequenting the North Atlantic 
Ocean. STEENSTRUP and LirKEN published in 1861 a memoir in which a Pennella was 
described as attached to a Hyperoodon rostratus captured in 1855 south of the 
Faroe Islands ; they named the parasite Pennella crassicornis. They referred to an 
observation made some years previously by von Dtpen that a Pennella, species not 
named, had been obtained from a Finner whale. In 1866 G. O. Sars stated that 
Specimens of a Pennella with the head buried in the blubber were seen attached 
to Balenoptera musculus. In 1877 Koren and Dantgtssen published a memoir on a 
Pennella found on Balenoptera rostrata, and preserved in the museum at Bergen, 
which they had named Pennella balenoptere twenty years previously. Other 
specimens from B. rostrata, buried with the head and horn-like arms in the blubber in 
the vicinity of the external organs of generation, had subsequently been added to this 
museum. VaN BENEDEN, in his memoirs on the natural history of the Cetacea, referred to 
these Balzenopterze as serving as hosts for a Pennella; and he further stated, though 
without giving very definite authorities, that this parasitic crustacean had also been 
found on Balenoptera sibbaldi, and probably on B. borealis. 
* Dr Traquair showed at the meeting of the Royal Society at which this memoir was read two dried 
specimens of Pennella exocexti, which he had received in November 1904 from Captain Parmr. It appears that when 
Captain Pater was on a voyage in the South Pacific a flying fish flew on to the ship ; and deeply rooted in the wall of 
its abdomen, behind the pectoral,fin, were the two specimens of Pennella, which he removed and sent to the Royal 
Scottish Museum. 
