506 TRANSACTIONS OF SECTION. D. 
in front connected through a narrow cesophagus and pharynx with the mouth. 
In the stomach is always found a large, concentrically laminated ovoid body, 
probably of excretory nature. There are two rounded ovaries in the cephalon, 
each sending out a transverse narrow process reaching its fellow in the middle 
line ; an oviduct passes laterally from each ovary to the genital opening, narrowing 
in the third thoracic segment and again widening, where it opens into the short 
vaginal duct. Close to the genital opening debouches a short duct from an 
unpaired receptaculum seminis, surrounded by a mass of unicellular glands, 
The adult male is much smaller, at most ca. 2 mm. in length. It seems quite 
unlike the female, slender, sub-cylindrical, curved, and resembling an insect- 
maggot, but closer inspection reveals fundamentally the same structure, the 
same appendages, &c., as in the female; the antennules somewhat less 
clumsy, the maxille larger and stronger, the thoracic feet almost thread-like, 
in young individuals, with a proportionally large inner branch, rudiments of 
which are generally preserved in the adult on the second and fourth pair. The 
body tapers into the post-abdomen, the genital part of which bears lateral out- 
growths corresponding to those of the female but firmly chitinised and back- 
wardly directed. The alimentary canal is like that of the female, the testes and 
their ducts corresponding in form and position. The distended terminal part of 
the sperm-duct contains the spermatophore, with a long thread-like neck reaching 
through the whole duct close to the testis. 
The Nauplius has the typical three pairs of appendages and two simple caudal 
sete; eyes are wanting as in all later stages. At the first moult a pair of 
maxillulcee are added, as small cylindrical warts, each with a long terminal seta. 
This first Metanauplius changes into a second, provided in addition with a pair 
of large mazilie and two pairs of bifurcated swimming-feet, and rudiments of a 
third and fourth pair. The fourth stage is very interesting: the maxillule are 
completely lost; the outer branch of the antenne forms an empty cuticular case 
without any sete; both branches and almost the whole stem of the mandible 
are likewise empty, naked sheaths, only at the very base enclosing a minute 
papilla of tissue; the maxille# are increased in size and directed forwards, the 
first and second pair of feet more fully developed, the third and fourth below, 
but still small ; the four thoracic segments are distinct, and a post-abdomen indi- 
cated. The fifth stage is a ‘ Cyclops-stage,’ with a short, triply-segmented 
post-abdomen, four pairs of swimming-feet with short sets on both branches; 
the mandibles are completely lost, the antennz short, slender, and unbranched. 
This stage changes into the C'yclops-larva (sixth stage) found outside the maternal 
gall. This is elongated, laterally compressed; the slender three-segmented 
post-abdomen is short; it contains no trace of an intestine or anus; the terminal 
segment is provided with two pairs of plumose setz (all the previous stages have 
only the two nauplial caudal set), but without furcal appendages. The anten- 
nules, hitherto of the simple three-segmented type of the nauplius, are now 
composed of seven segments, carrying several set, especially along the anterior 
border, and three large aesthetascs. ‘The small, short antennz show three slender 
joints, the last with two terminal sete; the maxille are three-segmented with 
curved terminal claw. The four pairs of thoracic feet consist each of an un- 
segmented stem and a larger outer and a smaller inner plate-shaped ramus, 
the first with five, the latter with three stiff, non-plumose sete. This larva— 
as already stated—moults and changes into the parasitic form (seventh stage), 
which by-and-by attains the size and shape of the adult. 
The systematic position of the new genus I am unable to indicate at present. 
It seems not to be related to any parasitic copepod known to infest other 
echinoderms. The ectoparasitic Asterocherida@ seem to differ widely; and the 
endoparasitic Pionodesmotes phormosome (Bonnier), shortly mentioned and 
figured by Richard (1910) as living in galls inside the shell of Phormosoma 
uranus (W.Th.) as well as ‘ Philichthys amphiure’—hitherto the only endopara- 
sitic copepod found in any ophiuroid—provisionally described by Hérouard 
(1906), are both so incompletely known that no real judgment can be made con- 
cerning their structure or possible relation to our new genus (or any other 
parasitic copepod). 
