US 
ZOOLOGICAL LITERATURE. 
somiteS; of which the posterior is terminated h}'’ four small hooked spines 
which antagonize with each other so as to form pincers. The first pair of 
legs, situated at the base of the antenno3 [these must be the second pair of 
antennre], are long and robust, and terminate in a strong hook. These are 
followed by the short oral appendages and four pair of biramose append- 
ages. Eye central, anterior, and single. Male and young unknoAvn. 
Ceratrichodcs albidus, gen. et sp. nov., Hesse, >p. 7o, pi. iv. fig. A-A 11, 
in a social Ascidian. Male. Length scarcely a millimetre. Animal 
gradually decreasing from the cephalon to the extremity of the pereion. 
Cephalic buckler equal in length to the three folloAving somites ; the frontal 
margin is round ; folloAving the cephalon are six somites of equal length, of 
Avhich the posterior is cordiform ; behind this is the pleon, which consists of 
eight somites of subequal length, except the posterior, Avhich is as long as 
the four preceding; the last somite supports a pair of long narrow flat appen- 
dages, furnished Avith two long and tAvo short spines. On the inferior cen- 
tral margin is a small lobe that is surrounded by a projecting margin; in the 
centre of this is a point that is perhaps an eye, on each side of Avhich is an 
antenna belonging to the first pair. They are very large, cylindrical, consisting 
of 7 or 8 articulj, of Avhich the first, or basal, is the largest. At the base and 
beneath these antennm are tAvo broad flat ciliated plates [second pair of 
antennte], the anterior margin of which is furnished Avitli two or three 
single articuli, furnished Avith cilia. The oral apparatus is a little posterior 
to the antennre, and the pereiopoda consist of four biramose pairs. Seen 
laterally the posterior somite of the pereion sIioaa'^s a large ovate opening on 
each side, of Avhich the margins are furnished, one Avith tAvo teeth, the other 
Avith one, that corresponds in position Avith the space betAveen the two. 
These openings appear to be genital orifices, and are surrounded by a 
membrane Avhich enlarges or contracts itself at need. The female is smaller 
than the male, and resembles it dorsally, except in the length of the pleon, 
Avhich is reduced to tAvo somites, and furnished with short stout caudal ap- 
pendages. 
JUotvyllopMus viridis, Ilesse, p. 70, fig. E~E 7. The author here describes 
the male; the female Avill be found described 1. c. t. i. 1864, found in a 
Botryllus. 
OjjhthalmaiKichus ruher, gen. et. sp. nov., Hesse, t. vi. 1866, p. 80. fig. F-E 1, 
in a red compound Ascidian. This genus closely resembles Biocryptes and 
Ilypnodes. The animal is robust, and gradually diminishes from the cephalon 
to the posterior extremity. In the male the cephalic buckler is less large 
and narroAA’^ anteriorly than pcsteiiorly. The frontal border is round. The 
pereion consists of five nearly equal somites, folloAved by five other subequal 
somites, of Avhich the last is the largest, and terminates in a pair of flat ap- 
pendages. The eye is placed dorsally in the centre anteriorly. Antennae 
very large, cylindrical, truncated at the extremity, consisting of three or four 
artierdi furnished Avith flexible hairs. Immediately beloAv the antennae is a 
large flattened jaw-foot [second pair of antennae], fumished at the extremity 
Avith rigid hairs. Pereiopoda four pairs, short, robust, biramose. Female 
shorter and stouter than the male. 
Platythorax alhidus, gen. et sp. no\'., Hesse, p. 82, pi. iv. fig. H-I) 1, in a 
broAvn pustulated compound Ascidian attached to Maia squinado. Female. 
Length 3 millimetres, breadth IL Cephalic buckler short and rounded ante- 
