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ENTOMOSTRACA, SIPHONOSTOMA. 203
lated; thorax 4-articulated; thoracic feet simple, flat, triangular, terminated
by a cfew; two-pointed corneous prolongations at the extremity of the abdomen.—A.
rufus, sp. n., found in the interior of a social Ascidian, [Rectius
Haplopus, but then preoccupied.]
SIPHONOSTOMA.
The parasitical Crustacea living on Annelids have been among
the last subjects of study to two observers of first rank, both now
deceased, M. SARS and E. CLAPAREDE. The latter has revised
the known genera from the original descriptions, and in comparison
with his own observations. He arranges them as
follows:—
1. PcecUostoma, Thorell (Ergasilidce) :—Selius, Kroyer, 1837; Terebellicola,
Sars, 1861; SabelliphUus, Sars, 1861; Chonephilus, Sars, 1861.
2. Siphonostoma proper ( Caligidce and Lernceidce):—Silenium, Kroyer, 1863;
Herpyllobius, Steenstrup and Liitken, 1861, perhaps the same as the preceding
; Sabellacheres, Sars, 1861; Nereieola, Keferstein, 1863; and Chelonidiformis,
Hesse, 1869. Ann. Sc. Nat. (5) xiii. pp. 1-9. M. Sars adds
two new genera, and identifies Selius with Silenium, Kundsk. Christ. Faun.
p.l.
ERGASILIDCE.
Bomolochus belones (Burmeister). The subject of a careful morphological
and anatomical description by Rob. Hartmann, Arch. Anat. Phys. 1870,
pp. 116-153, pis. 3,4. He found this parasite on the inside of the opercula of
the Sea-pike or Gar (Belone), as well in the Mediterranean as in the German
Sea.—B. ostracionis, sp. n., Richiardi, Arch. p. Zool. ii. pp. 47-59, pi. 1, fully
described, from the inside of the gill-opening of Ostraeion cornutus, from
Mozambique.
SabelliphUus sarsii, sp. n., Claparede, Ann. Sc. Nat. (5) xii. p. 10, pis. 7-15,
Naples, on the body of Spirographis spallanzanii. The species is fully described,
and the genus stated to be very nearly aUied to Lichomolgus,
Thorell.
CALIGIDJE.
Ccdigus [?] hyalinus, sp. n., Czerniavski, Mater, zoogr. Pont. p. 56, pi 8.
figs. 45,46, free-swimming between Alga?.
Silenium crassirostris [-e], sp. n., M. Sars, I. c. p. 2, pi. 8. figs. 10-15. Corpus
femince sacciforme, subglobosum, album, levissimum, antennis pedibusque
destitutum. Acetabulum in media fere longitudine corporis situm, tubulosum,
valde crassum, crassitudine tertiam ferme partem latitudinis corporis
sequante. Sacculi ovigeri ignoti. Mas minutissimus forma Cyclopis, cephalothoracelatiore,
quadriarticulato, antice in acetabulum elongatum conicoacuminatum
producto; cauda graciliore, triarticulata, appendicibus duabus
(furca) brevibus crassiusculis, setis 3 natatoriis armatis pra?dita. Antenna?
nullse. Maxillipedes duo triarticulati, articulo ultimo hamato. Tria paria
pedum natatoriorum, biramosorum, ramis uniarticulatis, exteriore ad apicem
setis natatoriis 5, interiore illo breviore setis 2 pra?dita. Drobak, near Christiania,
on the back of Polynoe dispar.