56 PERCY SLADEN TRUST EXPEDITION 
by a bluntly rounded lobe which, however, is conspicuous in dorsal view (fig. 3). The 
gastro-hepatic groove is well marked laterally, but is feebly developed in the mid-dorsal 
Ine. The cervical groove is distinct throughout. 
The cornea of the eye is large, scarcely depressed, and is noticeably wider than the 
stalk. Seen from above it is broader than long and its length is a trifle less than that of 
the stalk. At the distal end of the stalk, on its inner and superior aspect, there is a small 
round lobe, similar to that found in S. kroyert, Bate, but shorter and less cylindrical. 
The basal segment of the antennular peduncle is about as long as the two following 
taken together. The second and third segments are stout, the latter slightly longer than 
the former. The breadth of the second is contained about two and a half times in the 
length of its internal margin ; the third is scarcely three times longer than broad. 
The antennal scale is not very broad at the apex (decidedly less so than in S. robustus 
and S. bisulcatus); the lamellar part slopes directly away from the stout spine which 
terminates the outer margin and does not project beyond its base as in several of the 
allied species. 
The basal segments of the third maxillipedes are not stouter than those of the third 
pareeopods, and the two distal segments bear bristles on both margins. Above the base of 
the third perzeopods are two well-formed pleurobranchs, the upper nearly half the length 
of the lower. The upper branchia above the fourth pair of legs is a little longer than the 
similarly situated branchia on the preceding segment ; it is about two-thirds the length of 
the lower branchia. 
The form of the petasma, shown in fig. 4, differs considerably in detail from that of 
any species of the same group of which figures are extant. 
The outer uropod (fig. 5) is four times as long as broad; the length of the ciliated 
part at the distal end of its outer margin is exactly one-third of the total length of the 
segment. 
The specimens are not in very good condition, but the characters given above are, 
I believe, amply sufficient for the recognition of the species. SS. gardineri belongs to the 
robustus group of the genus Sergestes, which in Hansen’s amended account* comprises 
eight species. It is readily separated from S. challengeri, Hansen, and S. gloriosus, 
Stebbing, by the absence of photophores and from S. japonicus, Bate, and S. profundus, 
Bate, by the large size of the eyes. From S. robustus, Smith, S. bisulcatus, Wood-Mason, 
S. prehensilis, Bate, and S. kroyeri, Bate, it is distinguished by details in the structure of 
the rostrum, eye, antennal scale and outer uropod. It is, apparently, in the last of these 
species that it finds its nearest ally. 
3. ?Sergestes edwardsi, Kroyer. 
Sergestes edwardsi, Hansen, Proc. Zool. Soc. London, 1896, p. 961. 
Sept. 27, 1905. S. by E. of Farquhar, 10° 27’ S., 51° 17’. r. 500—250 fms. ; 
one male, ca. 18 mm. 
June 30, 1905. 7 miles N.W. of Yéyé, Peros Atoll. N. 400—0 fms.; one male, 
one female, ca. 13 mm. 
* Hansen, Proc. Zool. Soc. London, 1896, p. 949, amended in Proc. Zool. Soc. 1903, p. 71. 
