PowELL.—On Desis robsoni. 263 
Fig. B.1. Cypris littoralis: (a) superior antennz; (b) inferior antennæ; (c and d) first 
and second pair of legs 
"al 
Cythere atra: (a) portion of valve ; (b and c) legs of first and second pairs. 
e 
. Loxoconcha punctata: (a) superior antennæ ; (b) inferior antenne; (c) man- 
dible; (d) maxille; (e) third pair of legs; (f) outer margin of valve; (g) 
hinge-line ; (h) abdominal lobe; (k) post-abdominal ramus 
Fig. C.1. Cythere atra : (a) superior antenne ; (b) inferior antenns. 
be 
Cythere truncata: (a) superior antenne ; (b) inferior antennz ; (c) mandible. 
oo 
. Philomedes agilis: (a) central portion of valves showing lucid spots; (b) por- 
tion of seta on natatory branch of lower antenn:s, female; (c) second 
joint of lower antenne, male; (d) same, female; (e) extremity of oviferous 
foot 
Fig. D.1. Philomedes agilis: (a) superior antennæ, male; (b) same, female; (c) natatory 
branch of inferior PENA male; (d) same, female; (e) mandibular foot ; 
(f) post-abdominal laminæ ; (g) second maxillæ ; 
- Cyclops nove-zealandie, iet : (a, b) superior and inferior antenne; (d) second 
foot-jaws, outer branch; (e) inner branch; (f) leg of third pair; (g) leg of 
fifth pair; (A) caudal lamelle and set»; (k) second segment of abdomen 
with triple spines; (J) superior antenne of male. 
bo 
o 
. Arpacticus bairdii, female: (a) foot-jaws; (b) first pair of legs. 
Fig. E.1. Arpacticus bairdii, female: (a) inferior antenna; (b) superior antenne; (c) 
cephalothorax from above; (d) third pair of legs; (e) fifth pair of legs; (f) 
abdominal segments and caudal sets. 
Daphnia obtusata: (a) head, seen from a ; (b) superior antenne; (c) 
mandibles; (d) extremity of abdomen; Ui NENE taken from carapace of 
‘as 
arent. 
3. Chydorus minutus: (a) inferior antennæ ; (b) superior antenne ; (c) extremity 
of abdomen 
. Lepidurus kirkii: (a) foot of the first pair. 
5. Lepidurus compressus : (a) foot of the first pair. 
d» 
Art. XXII.—On Desis robsoni, a Marine Spider, from Cape Campbell. 
By Luewettyn Powell, M.D. 
[Read before the Philosophical Institute of Canterbury, Tth November, 1878.] 
Plate XII. 
Ix the tenth volume of the Transactions, p. 299, is a short description of 
& spider, discovered inhabiting old Lithodomus holes, beneath the surface 
of tidal pools, by Mr. C. H. Robson, at Cape Campbell. Dr. Hector in a note 
states that this spider is allied to the genus 47gyroneta, and proposes for it 
the name Argyroneta marina, 
