78 ON CRUSTACEANS IN THE ‘CHALLENGER’ COLLECTION. [Jan. 20, 
EXPLANATION OF THE PLATES. 
Prate XI. 
1. Petalidium foliaceum Bate. p. 54. 
a. Rostrum of a specimen from Stat. 159, from the side. 
6. Kye and left antennular peduncle of the same specimen, from above. 
c. Rostrum of a specimen from Stat. 146, from the side; X 5. 
d. Eyes of the same specimen, from above; slightly more than X 5. 
e. Basal part of mxp.2—mxp.® and _ trl.4—trl.®, together with the branchial 
apparatus of the last-named specimen; X 5. 67., rudimentary pleuro- 
branchia to mxp.2; ep., epipod on mxp.? with its branchia; /., four 
pleurobranchial lamelle belonging to mxp.? and trl.i—tr]3 
1f. Lateral view of the front part of the scutum and the eye of a young speci- 
men—measuring 21°5 mm. in length—trom Stat. 158. 
lg. Rostrum and eyes of the same specimen, from above. 
2. Petalidium sp. p. 55. 
Fig. 2a. Front portion of the scutum of a young specimen from Stat. 137, described 
by Bate as Sergestes profundus Bate. 
3. Sergestes profundus Bate. p. 69. 
Fig.3a. Front part of the scutum, eye, and antennular peduncle of the specimen from 
Stat. 300; 15/2. 
35. Rostrum of the same specimen. 
4. Sergestes prehensilis Bate. p. 56. 
Fig. 4a. Rostrum, eye, and base of the antennular peduncle, from the side. 
4,6. Front end of the scutum, eyes, peduncles of the antennulee and squamz, 
from above. 
5. Sergestes kroyeri Bate. p. 58. 
. Rostrum, from the side. 
. Front end cf the scutum, left eye, and the peduncles of the antennulz, from 
above; X 4. 
6. Sergestes similis, n. sp. p. 69. 
Or 
oa 
Fig.6 a. Front end of the scutum, left eye, and peduncle of the antennula, from the 
side; X 14/3. 
6 6. Rostrum and supra-ocular spine, from the side; x 12. 
6c. Front end of the scutum, eye, peduncles of the antennule and squame, 
from above; X 5. 
6d. Branchie above trl2—trl4; x 11/2. 2br., first branchia to trl2; 27., 
branchial lamella to tr]2; 36,r., first branchia to trl.3; 3 br.1, second 
branchia to trl; &c. 
Prats XII. 
1. Sergestes arcticus Kr. p. 60. 
Fig.1q@. Front end of the scutum, eye, and basal portion of the antennular peduncle, 
from the side; x 9/2. 
1 6. Rostrum and supra-ocular spine of the same specimen; X 11. 
1c. Branchie above trl.2—trl; x 8. The lettering as im fig. 6d on the pre- 
ceding Plate. 
2. Sergestes challengeri, n.sp. p. 61. 
In the following figures o signifies luminous organs. 
Fig. 2a. Scutum, with the basal parts of the eye-stalk, antennula and antenna; 
x 5. 
26. Front end of the scutum, basal part of the eye-stalk, and antennular 
peduncle; X 17/2. 
2c. Front end of the scutum with the anterior appendages, from above; x 9. 
Of the eye-stalks only the basal joint remains; of the left squama the 
distal half is omitted; on the right squama the two distal ones of the four 
luminous organs are seen through the plate. 
