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Show 108 MR. F. E. BEDDARD ON ISOPODA COLLECTED [Feb. 2, 3. ARCTURUS CORNUTUS, n. sp. This species, like the last, is represented by a single female example, measuring 36 millim. ; the length of the antennae is 64 millim. The margin of the head is excavated dorsally and anteriorly ; the antero-lateral margin of the head below and in front of the eyes is notched ; between the eyes are a pair of long, forwardly-directed spines, and behind the eyes a pair of blunt tubercles. The first three thoracic segments are subequal, and each is a little longer than the fourth. Each of the segments is ridged as in the last species; the lateral margin of the tergum has a long spine in each of their segments, and there is another spine of equal length placed halfway between the dorsal median line and the lateral margin of the segment ; on the fourth segment there is an additional lateral spine placed behind the principal spine ; there are indications of a corresponding spine in the anterior segments. The epimera of segments 2-4 have a single spine near to their posterior margin, the lengths of which increase progressively from before backwards ; in front of the posterior tergal ridge are a pair of blunt tubercles united by a slight elevation ; the first segment has also a single tubercle placed in front of this. Each of the three posterior segments is ridged as in A. anna ; laterally is a long spine which overlies a similar spine upon the epimeron ; the first of these segments has also a somewhat longer epimeral spine directed forwards. Each of the three free abdominal segments has along lateral spine ; the first segment has ventral spines as in the last species. The abdominal shield has the same shape as in A. anna, but there is a distinct longitudinal keel terminating in a sharp upturned point; on either side is a single row of curved hooklike spines. The 2nd, 3rd, and 4th pairs of thoracic limbs have spines similar to those of the last species. Station 214; 500 fathoms. 4. ARCTURUS BRUNNEUS, n. sp. This species measures 19 millim. in length, the antenna? being of about the same length. The head is furnished with a pair of long spines between the eyes, and a pair of shorter spines behind these, which are, however, longer in the female. The first four thoracic segments are subequal, ridged as in the last two species ; on this ridge are implanted a number of long, straight, slender spines. In the male the first segment has four equidistant spines and a minute epimeral spine at the extreme lateral margin; on the second segment the epimeral spine is longer, and there is a minute tubercle between it and the lateral tergal spine; in the third and fourth segments the lateral tubercle is developed into a spine, and there is also a short median dorsal spine ; on the second, third, and fourth segments there is a transverse row of longish spines near to the anterior margin of the segment in both sexes; in the female the spines are longer. Each of the three posterior thoracic segments bears a ridge, with a single row of long spines arranged at equidistant intervals ; there are three pairs of these spines, one pair epimeral; in the |
