10 



MAKINE ISOPODS FROM THE PHILIPPINE ISLANDS. 



has the posterior extremity slightly produced beyond the postlateral angle of the 

 segment. The last three have the posterior extremities very acutely produced and 

 extending considerably beyond the postlateral angles of the segment, the last reaching 

 as far as the postlateral angles of the third abdominal segment. 



The first abdominal segment is entirely concealed by the seventh thoracic segment. 

 The three following segments are short and subequal. The fifth segment is a little 

 longer in the middle than any of the preceding segments. The sixth or terminal 

 segment is triangular, with apex rounded-truncate and furnished with hairs. The 

 outer branch of the uropoda is narrow and produced to a blunt extremity. The inner 

 branch is twice as wide as the outer branch, has the posterior margin straight in the 

 middle, with the inner postlateral angle rounded and the outer postlateral angle 

 produced to a blunt extremity. The last three segments of the thorax, the abdomen, 

 and the uropoda are thickly covered with stiff setae, or spines, those on the abdomen 

 becoming denser and longer. The first three pairs of legs are prehensile, the last four 

 pairs ambulatory. The prehensile legs have the merus armed with four spines. 



Only one specimen, a female, was collected at station 5254, Linao Point, N. 44° E., 

 1 mi. (7° 02' 00" N., 125° 37' 45" E.), at a depth of 21 fathoms, in sand and coral. 

 Type specimen, catalogue number 40911, United States National Museum. 



I have placed this species in Stebbing's genus Argathona a notwithstanding the slight 

 difference in the form of the second maxilla, which, instead of ending in a curved, 



a bee 



Fig. 8.— Argathona setosa. a, Abdomen, X 9§; b, maxilliped, X 271; c, first leg, X 20£; d, first maxilla, 



X 38$; e, second maxilla, X 51f . 



sharp unguis, seems to end bluntly. There is also an additional article to the maxil- 

 lipeds, btit this may have been overlooked in Stebbing's specimen. 



This species is very similar to Stebbing's species, Argathona normani, but differs in 

 lacking tubercles on the last two thoracic segments and on the fourth, fifth, and sixth 

 segments of the abdomen. The shape of the inner branch of the uropods is also differ- 

 ent. Stebbing's specimens were from the Gulf of Manaar and south of Galle. 



Argathona sulcata, sp. nov. 



Body oblong-ovate, 2.5 times longer than wide, 8 mm.: 20 mm. Surface smooth. 

 Color light yellow. 



Head wider than long, 2 mm.: 3.5 mm. Anterior margin rounded and produced in 

 the middle in a very small, median point. Eyes twice as long as wide, 0.5 mm. : 1 mm., 

 composite, and situated in the postlateral angles. The first pair of antennae have the 

 peduncle composed of two articles, the first somewhat dilated ; the flagellum, which is 

 composed of thirteen articles, extends to the posterior margin of the head. The 

 second pair of antennae have the first three articles short and about equal, and do not 

 extend beyond the peduncle of the first antennae; the fourth and fifth articles are 

 long and slender, and extend to the end of the first thoracic segment; the flagellum, 

 composed of thirty-seven articles, extends to the posterior margin of the sixth thoracic 

 segment. 



o Ceylon Pearl Oyster Fisheries Report, 1905, pt. iv, art. xxm, p. 16-18, pi. in A. 



