Crasslcaiula cras.'^icaiula {Crcpl.) and its Hosts. 1-45 



led'^G of the Cetacc.i, and lias, at my request, examined the 

 descripfion o£ Rosenthal and Ilornschuch and that of 

 Milliter, informs mo that, in his opinion, tlie facts point to 

 the conclusion that tho whale in question was a common 

 rorqual {JJahnnoplera piti/salus, \j.=-Ii. muscu/iis, ancit.) and 

 not a Ijliie whale. The main reasons for this conclusion, 

 stated briefly, are : — (1) The general coloration of the body 

 — bhick above, white beneath ; (2) the colour (white) of the 

 first ninety baleen-plates on the riglit side (this asymmetrical 

 condition is highly characferi.stic of the common rorqual) ; 

 ('.\) the comparatively small breadth of the baleen-plates : 

 (4) the number of vertcbrai (Gl) and of pairs of ribs (15) ; 

 (o) the number of Hnger-bones ; ((I) the figures representing 

 the external appearance of the animal, reproduced by Munter 

 from drawings made in 1825 (these, in Dr. Ilarmer's opinion, 

 '* indicate the common rorqual rather than the blue whale '') ; 

 (7) the montii (April) in which the 1825 whale was stranded. 

 The blue whale seldom appears off the Norwegian coasts 

 before the end of May or beginning of June. 



It is somewhat remarkable that Diesing * has recorded 

 the host of ('replin's original material as '■^Balcvna hurealis,^^ 

 while von Linstow f has included the parasite (the reference 

 being to Creplin's material) among those of Balcena mysti- 

 cclus, L. It may be supposed that both these records are 

 erroneous ; they were doubtless due to the uncertainty 

 existing as to the determination of the 1825 whale. 



In the case of the 'Terra Nova' material the host was 

 another baleen whale, Megaptera nodosa, taken off New 

 Zealand. Mr. J. E. Hamilton, who has been investigating 

 various questions connected with whales at the Belmullet 

 Whaling Station, states in his report for 1914 J that he 

 fouiul " Nematode worms of some size '* in the urinary 

 vessels of twenty-one finners {B. phj/salus), in one blue 

 whale {B. muscultis), and in the scjhval [B.horealis, Lesson). 

 These worms, j\Ir. Hamilton considers, are very closely allied 

 to, if not identical with, Crassicauda crussicauda. It is of 

 especial interest to note that they occurred most commonly in 

 B. jthysalus, a fact which lends great probability to the view 

 that the host of the types belonged to that species. 



The parasite evidently has its normal habitat in the urino- 

 genital system of its host. In Creplin's original case the 

 worms were discovered in the corpoia cavernosa of the male 



* ' Syslenia Ilelmiuthum/ 18r>], p. 204. 

 t ' Compendium der Ilelmiuthologie,' 1878, p. Gl, 

 X British Association Keport, 1915, " Report on Belniullet Whaling 

 Station." 



Ann. d: May. N. Hist. Ser. S. Vol. xvii. 10 



