ANCHIALINA OBTUSIFRONS. 197 
17. Anchialina obtusifrons, sp. nov. 
Plate 2, figs. 4a-4e. 
Butaritari, Gilbert Islands. Jan. 6, 1900. Lagoon. Surface. Light. 2 adult males. “Albatross.” 
Description.— This species is in most particulars closely allied and similar 
to A. grossa. Frontal plate in the male (fig. 4a) less broad than in A. grossa 
and produced in a long rostrum reaching slightly beyond the eyes; this rostrum 
has the lateral margins a little concave, these being proximally somewhat con- 
verging forward and distally parallel, while the end of the rostrum looks nearly 
truncate, but its terminal, obtusely triangular portion is in reality bent down- 
wards and backwards below the apparently terminal part. The eyes are brown 
and slightly larger than in A. grossa, broader than the end of the stalk which 
widens considerably from the base outwards. 
Third joint of the antennular peduncle less thick and conspicuously longer 
than in A. grossa, being half as long again as broad. Antennal squama about as 
in A. grossa. ; 
Gnathopods (fig. 4b) nearly as in A. grossa; second joint very large and 
much longer than broad; fifth joint strongly expanded, and from the inner side 
with a very large, lamellar, oblong-triangular, distally blunt process directed 
inwards and much forwards; sixth joint broad. First pair of thoracic legs as 
the following pair, with sixth joint divided into three subjoints. 
Exopod of third male pleopods (fig. 4c) in the main as in A. grossa, with 
the distal joints much altered and furnished with several processes which 
constitute a most complex organ, though different in several minor particulars 
from that in A. grossa. The gigantic lamellar process (a.) on the posterior 
outer side is much narrowed somewhat before the end and its most distal part 
is also a little widened; the joint (b.) bearing the terminal processes is much 
longer than in A. grossa, with a terminal, lamellar expansion covering in front 
the insertion of these processes (c., d., and e.); finally, the inner process (e.) has 
more than its distal half very slender, the ramification of the median process 
(d.) is somewhat different from that in A. grossa, and the very long outer process 
(c.) has its secondary branch (c.) adorned with a few low saw-like teeth. 
Uropods with the endopod reaching about the end of the telson and some- 
what longer than the exopod, which has the end broadly rounded, nearly trun- 
cate, and 15-17 spines along the outer margin.— Telson nearly as in A. grossa, 
but the proximal part of the terminal incision is narrower. 
Length 7.5 mm. 
