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XVIII.—On Pennella balenoptere: a Crustacean, parasitic on a Finner Whale, 
Balznoptera musculus. By Sir William Turner, K.C.B., D.C.L., F.R.S. (With 
Four Plates.) 
(Read February 6, MS. received February 8, 1905, Issued separately May 26, 1905.) 
CONTENTS. 
INTRODUCTION . A - : ; : . 409 REPRODUCTIVE ORGANS A ; . : . 424 
EXTERNAL CHARACTERS OF THE FEMALE . eA) THe Mae . 5 5 ‘ : ‘ A « AIBAT 
CHITINOUS ENVELOPE . 5 : . : 5 othe! CoMPARISON WITH OTHER SPECIES ‘ < . 428 
STRUCTURE OF Heap . ; P : F . 414 CONCHODERMA . i : 3 F 4 . 430 
ALIMENTARY CANAL . ; F ‘ : . 419 BIBLIOGRAPHY . : ‘ ; 3 ; ~ 4oil 
Nervous SystrEmM 3 ‘ ‘ ake _ Abe) EXPLANATION OF PLATES . ‘ é : _ AB? 
PENNATE APPENDAGES F i : A AS 
INTRODUCTION. 
In September 1903 I received a bottle containing twelve specimens of a large 
parasite presented to me by Mr Cur. Casrperc, the manager of a Norwegian whaling 
company which has established a fishing station at Ronasvoe in the north of Shetland.* 
In his letters Mr Casrzere stated that the parasites were attached to a Finner whale, 
which, from its size, the mottled character of the whalebone and the pointed head, was 
obviously a Razorback—Balznoptera musculus. The parasites were numerous, and were 
fixed to the back of the whale, and the attached end penetrated through the skin into 
the blubber. Although Mr Casrpere had seen many hundred whales, this is the first 
occasion on which he had met with this form of parasite. 
From the characters of the specimens I concluded that they were a giant species 
of a parasitic Crustacean, of the family Lernzidz, and on further investigation I 
associated them with the genus Pennella (Oken). 
This genus is now regarded as including those members of the Lernzeidze which, as 
studied in the females, have the head stunted and club-shaped, with horn-like arms 
radiating from its base ; the body elongated, cylindriform, not bent into a sigmoid shape ; 
the anterior part of the body attenuated, but widening further back; a pair of genital 
openings with depending ova strings; the terminal part of the body caudate, giving 
origin to the characteristic bristle-like pennate appendages ; pairs of minute rudimentary 
feet springing from the ventral surface of the body close to the base of the head. 
From the time of Aristotle, naturalists had recognised that the Tunny and Swordfish 
were infested by worm-like parasites, fastened to the skin near the fin. RoNnDELETIUs, 
* I am indebted to my valued correspondent, Mr THomas ANDERSON, merchant, of Hillswick, Shetland, for 
putting me into communication with Mr CasTBERG. 
TRANS. ROY. SOC. EDIN., VOL. XLI. PART II. (NO. 18). 61 
