THE 
VOYAGE OF H.M.S. CHALLENGER. 
ZOOLOGY. 
REPORT on the Cirripedia collected by H.M.S. Challenger during the 
years 1873-76. By Dr. P. P. C. Hoek , Member of the Royal 
Academy of Science of the Netherlands. 
ANATOMICAL PART. 
INTRODUCTION. 
One of my principal reasons for wishing to investigate the Cirripedia dredged during 
the cruise of H.M.S. Challenger was the hope that I should be able by the aid of the 
deep-sea material to enlarge our knowledge of the morphology of the order. It was 
possible that among the forms from considerable depths there might be some which on 
account of their great size, or for other reasons, would be especially favourable for 
anatomical research, as was the case with some of the Pycnogonids from the abysses. 
It was possible also that among them a new form might occur, the investigation of 
which would cast light on details in the organisation which had not hitherto been suffi- 
ciently understood. In this respect, however, the study of the deep-sea material has 
somewhat disappointed my expectations ; the new forms for the most part are represented 
by single specimens only, or are too small to be dissected advantageously. I have 
therefore been obliged to limit 'my researches entirely to such forms as were previously 
known and had served for the researches of former investigators. They belong to the 
genera Lepas , Conchoderma, and Scalpelluin of the pedunculated Cirripedia, and to the 
genus Balanus of the sessile Cirripedia. What I have been able to work out does not 
form a connected whole, but may conveniently take the form of separate chapters in the 
morphology of the group. 
(ZOOL. CHALL. EXP. — PART XXVIII. — 1884 .) 
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