MARINE ISOPODS FROM THE PHILIPPINE ISLANDS. 



31 



segment the lateral tubercles are larger and are not placed in a regular transverse line. 

 The lateral parts of the segments are produced in elongated processes, with straight 

 lateral margins, and are surrounded on all three sides by a fringe of sharp teeth close 

 together. On the dorsal surface of these lateral parts of the segments are numerous 

 small bodies, similar to those on the tubercles. The seventh segment is not pro- 

 duced laterally in processes. 



The abdomen consists of two segments, the first of which is short and has a transverse 

 row of ten tubercles, similar to those on the thorax. At the sides, just lateral to the 

 four median tubercles, is an upper transverse row of four tubercles on either side and 

 the lateral parts of this segment are produced on either side in an elongated process 

 similar to those of the thorax, but double-lobed on the lateral margin, fringed with 

 teeth and having numerous small bodies on the dorsal surface. The sixth or terminal 

 segment is triangular, with apex rounded. On the dorsal surface are three transverse 

 rows of six tubercles, three on either side of the median line, and a fourth row of three 

 tubercles, one in the median line and one on either side, all similar to those before 

 described. Below the last row of tubercles the dorsal surface is covered with the 

 small disk-like bodies, and the entire margin of the segment is fringed with sharp 

 teeth. The branches of the uropoda are of nearly equal length, the inner, immov- 

 able branch being a little wider than the outer branch; they extend to the extremity 

 of the terminal abdominal segment. Both are fringed on all the margins with sharp 

 teeth and have small disk-like bodies on the dorsal surface. They are posteriorly 

 rounded. 



All the legs are similar, ambulatory. 



The pleopods of the fourth and fifth pairs have both branches similar, of fleshy 

 appearance and without marginal setae. The exopod of the fifth pair is not two- 

 joirjted. 



This genus belongs, therefore, to the section of eubranchiate Sphaeromidse of Han- 

 sen, but corresponds to none of the described genera. 



Only one specimen was collected, at station 5661, Flores Sea, Cape Lassa, at a depth 

 of 180 fathoms. Type, catalogue number 41024, United States National Museum. 



IDOTEOIDEA. 

 Family ARCTURID^. 

 Genus ARCTURUS Latreille. 

 Arcturus cornutus Beddard. 



Arcturus cornutus Beddard, Proe. Zool. Soc. Lond., 1886, pt. 1, p. 108; Challenger Report, Zool., 

 vol. 17, pt. 48, 1886, p. 93-94, pi. xix, fig. 6-12. 



Locality: Station 5621, between Gillolo and Makyan Island, at a depth of 298 

 fathoms, and station 5605, Gulf of Tomini, Celebes, Dodepo Island, at a depth of 647 

 fathoms. Two specimens. Beddard's specimen was from off Samboangan. 



Arcturus parvus, sp. no v. 



Body elongate-ovate, covered with long spines; 8 mm. long : 1.5 mm. wide. 



Head with a deep median excavation. Eyes large, round, composed of numerous 

 ocelli. There are two long spines on the anterior portion of the head, between the 

 eyes, one on either side of the median line, and two long ones on the posterior portion, 

 one on either side of the median line, and one small spine on either side of these. The 

 first pair of antennae have the first two articles subequal, the first somewhat dilated; 

 the third article is elongated, about as long as the first two taken together. The first 



