148 Part ITT.—Twenty-third Annual Report 
our shores. Figure 20 in plate x. shows one of the fifth pair of thoracic — 
feet of a female specimen. 
Fam. ASTEROCHERIDA, 
Genus Dyspontius, Thorell (1859). 
Dyspontius curticaudatus, sp.n. Pl. xui., figs. 1-10. 
Description of the Female——Length ‘8mm. (about ,; of an inch) ; 
somewhat similar to Dyspontius striatus in general appearance, but con- 
siderably smaller, except that the abdomen is also distinctly shorter, and 
the cephalosome rather more distinctly triangular in front. The 
abdomen and furcal joints are very short, and are together scarcely longer 
than the combined lengths of the preceding segments of the metasome 
fig. 1). 
; Fe cite Sl are short, moderately stout, sparingly setiferous, and 
composed of eight joints; second and last joints subequal and longer 
than any of the others; the fourth is short, being only about half the 
length of the joint on either side, as shown in the annexed formula :— 
Proportional lengths of the joints, 14° 25-10°:5:10:+8:10° 23 
Numbers of the joints, - . eM 2M Qarig7 08. wee Tie 
A short sensory filament springs from about the middle of the end joint 
fig. 2). ; 
fine antenne (posterior antenne) are moderately elongated, four- 
jointed, and armed with three moderately stout terminal spines, the 
middle one being considerably elongated and the outer very small; the 
outer ramus is rudimentary (fig. 3). The siphon reaches to about the end 
of the cephalosome. 
The mandibles are very slender, and a small portion of the distal end 
of the inner margin is coarsely dentate, as shown in the drawing (fig. 4). 
The maxille are somewhat similar to those of Dyspontius striatus, 
but are rather stouter, and the inner ramus is proportionally scarcely so 
elongate, being only slightly longer than the outer ramus; the terminal 
sete of the outer and inner rami are also similar to those of that species 
(fig. 5). 
The first maxillipeds resemble those of Dyspontius fringella, Giesb., 
very closely ; they are furnished with a small fringe of sete near the end 
of the second joint; the terminal claw is moderately short (fig. 6). 
The second maxillipeds have the second joint elongated, but the third 
and fourth, which are subequal in length, are together not much more 
than half the length of the second joint ; the terminal claw is stout and 
moderately short, and about equal to the combined lengths of the two 
preceding joints (fig. 7). 
The swimming feet resemble those of Dyspontius striatus. In the first 
pair neither of the two branches bear terminal spines ; the first joint of 
the outer branch, which is nearly twice as long as the next, carries a short 
seta on the distal angle of the outer margin, and another on the lower 
half of the inner margin ; the second joint bearsa short spine on the outer 
angle anda seta on the inner margin, while the last joint is furnished 
with two small spines on the outer margin, two sete on the inner margin 
and two more setz at the apex ; the first joint of the inner branches bears 
one and the second two setz on their inner margin, while the third carries 
three on the inner margin, one small seta on the outer margin, and two of 
moderate length at the apex, as shown in the drawing (fig. 8) ; the second 
pair, which were somewhat similar to the third, were damaged and no 
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