84 | g 
observed. The last thoracic segment is obtusely triangular in outline, with the apex very narrowly 
rounded. The rostrum is robust and strongly bifurcate. The rami are truncate at the apex and 
bear a moderately long curved filament. 
The abdomen is composed of four segments. The combined length of the abdomen and 
furca is contained about two and a half times in the total length of the cephalothorax, from 
the frontal margin to the base of the genital segment. The genital segment is rather shorter 
than the combined length of the second and third segments. The anal segment is very small 
and is equal to about one-third of the length of the third segment. The furcal joints are as 
long as broad, and are equal to the length of the anal segment. 
The antennules are composed of twenty-four joints, and extend to the end of the second 
abdominal segment. The basal joint of the antennules appears to be divided. 
The antennae, mandibles, maxillae and maxillipedes are similar in structure to those 
of Cornucalanus chelifer. The curved spine on the apex of the first maxilliped, is furnished 
with a fringe of short hairs on the middle of the internal and external margins. The internal 
base of the spine carries a short stout process, which is produced at the apex into a long 
whip-like seta. The apex of the first maxilliped bears six short sensory organs with tufted heads, 
and two long simple filaments. 
The four pairs of swimming feet are similar to those of Oxchocalanus. 
dhe mirth ti panwotteet ismvery, small. Each foot consists of two free joints attached to a 
basal part. The first joint is furnished with a small tuft of spinules at its posterior end. The 
second joint is furnished with three or four transverse rows of spinules. The joint terminates 
in two small apical spines. 
No figures of Cornucalanus simplex have previously been given, but so far as WOLFENDEN’S 
very brief description goes, the ‘Siboga’ form appears to agree with that species. The ‘Siboga’ 
specimen is an adult female, and by the absence of the cephalic spine is evidently distinct from 
Cornucalanus chelifer. The remarkably strong and curved claw with the peculiar process at 
the base, on the apex of the first pair of maxillipedes, is sufficient to separate this genus from 
any of the other members of the family Phaennidae. 
Occurrence. — One female was obtained from the plankton collected with the HENsEN 
vertical net at Station 143, 1000 metres to the surface. 
Genus Amallophora T. Scott, 1893. 
This genus was established by my father in 1893, for a Calanoid, which was readily 
distinguished from any other known form by the presence of a peculiar appendage, resembling 
a sheaf of corn, on the apex of the first pair of maxillipedes. Other forms were included in 
the genus, but these are now clearly not congeneric. Amallophora was afterwards included under 
the genus Xanthocalanus by GiESBRECHT and SCHMEIL. 
Sars has recently revived the genus for the reception of one of the species originally 
included in it by my father. Farran rightly points out, however, that this use cannot be upheld, 
as Amallophora magna is not congeneric with Amallophora typica. 
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