ANNELIDA. 
601 
cirri ; three antennre. Includes Exogone kefersteinii (Clap.) and E. gemmi- 
fera (Pag.). The closely allied Microsyllis has but two antennae. Exogone 
proper differs from both these genera in possessing ventral cirri. 
Isosyllis. Palpi ] perisloniium with setae ; three antennae. Includes SylUs 
maculosa (M.-Edw.) and S. armoricana (Clap.) 
Oophylax. As last, but with four antennae. Includes Exogone eerstedii 
(Roll.) and E. cirrata (K611.). 
Eucerastes. No palpi; long cirri from all the segments; cirri thick, 
club-shaped. Sp. Myrianida clavigera (Schmarda). 
Baird describes, as new species : — 
Amphinome didymohranchiata (Island of Ascension). 
Cluxtopterus insiynis (British Seas). 
Heteronereis signata (Cornish coast). 
Fam. Serpulid;e. 
Euponiatus holtoni (New Zealand). 
Elagostegus cariniferus (New Zealand and C. B. S.). The Cape specimens 
constitute the variety termed krausii. Gray described the operculum of this 
Annelid as belonging to Vernietiis. Also P. latiligulatus and P. grayii (Hab. 
of both unknown). 
Cymospira tricornis (Djedda) ; C. hrachycera (Australian coast) ; C. mac- 
gillivrayi (Fiji Islands). 
Eomatostcgus howerhanki (Australia). 
Scrpidajukesii (Australia) ; S. narconensis (Narcon Island) ; S. zcylandica 
(New Zealand). 
The new forms described by Claparede are as follows : — 
AmpMglena. Branchige like those of Sahella ; setigerous expansions sup- 
porting a double series of dissimilar setae ; ocelli on the first and second 
segments (^— AmpTiicora^ Leydig). A. mediterranea (described as arniandi 
in the text ; but see author’s rectification at p. 688), the only species, has 
the sexes united. 
Fahricia armandi. An amended definition of Fahricia is given. 
Fam. Ariciidae. 
Aricia eerstedii ; Theodisca anserina. Theodisca is re-defined. 
Aonides, n. g. Head conical, with two rudimentary occipital antennae ; no 
buccal tentacles ; feet (parapodia) biramous, the notopodium furnished with 
a plate-like lobe ; anterior segments alone provided with ligulate branchiae. 
Near Aonis (Sav.), but at once distinguished by wanting the unpaired 
cephalic tentacle of that genus, and by the accumulation of the branchiae on 
the anterior segments. Also allied to Clytia (Gr.), which, however, is 
without occipital tentacles, and displays branchiae along its entire length. 
Aonides auricularia , the only species, is remarkable for the 
complex structure of its reproductive elements, which lie free 
within the cavity of the body. The ova are spherical, with 
distinct yelk, germ-vesicle, germ-spot, and a very thick chorion. 
The surface of this is elevated into numerous minute conical 
