MAEINE TSOPODS FROM THE PHILIPPINE ISLANDS. 



13 



articles subequal and not dilated; the third is about as long as the first two taken 

 together. The flagellum is composed of twelve articles and extends to the posterior 

 margin of the head. The second antennae have the first three articles short, the first 

 and third about equal in length and the second shorter; the fourth is about 1.5 times 

 longer than the third, and the fifth 1.5 times longer than the fourth. The flagellum 

 is composed of about thirty articles and extends to the middle of the fourth thoracic 

 segment. 



The first three segments of the thorax and the seventh segment are subequal, each 

 being 1.5 mm. long; the fourth, fifth, and sixth segments are equal in length, each 

 being 2 mm. long. Epimera are present on all the segments of the thorax except 

 the first. The first two are in the form of narrow plates with rounded extremities 

 not extending beyond the posterior margins of the segments; the following four pairs 

 are acutely produced posteriorly and extend beyond the postlateral angles, being 

 increasingly longer and more acute. 



The first segment of the abdomen is partly covered by the seventh thoracic segment. 



The following three segments 

 are subequal and each is about 

 0.75 mm. long; the fifth segment 

 is 1 mm. long; the sixth or ter- 

 minal segment is 3 mm. long 

 and 3.5 mm. wide at the base, 

 with sides gradually converging 

 to a rounded extremity which 

 has five small dentations on 

 either side of a triangular me- 

 dian one. The uropoda are simi- 

 lar in shape, with the posterior 

 extremity obliquely truncate 

 and the lateral and posterior 

 margins dentate; the inner 

 branch extends to the extrem- 

 ity of the abdomen; the outer 

 branch is shorter and smaller 



than the inner branch. Fig. 12.— JEga dubia. a, Female, X 2f; b, maxilliped, X 27i; 



The first pair of prehensile c, male, x 4. 



legs have one spine on the merus and one on the carpus; the two following pairs have 

 three spines on the merus and two on the carpus; the following four pairs are ambu- 

 latory and covered with numerous spines. 



The male is similar to the female, but differs in its smaller size, being only 14 mm. 

 long and 5.5 mm. wide, and in the different length of the segments of the thorax, the 

 first being 1.5 mm., the following four subequal and each 1 mm. long, and the sixth 

 and seventh together equal to 1 mm. 



Only two specimens, a male and a female, were collected at station 5218 (type 

 locality), Amina Sola Island (E.), N. 10° W., 2 mi. (13° ll 7 15" N., 123° 02 / 45" E.), 

 at a depth of 20 fathoms, in coarse sand, and station 5134, Balukbaluk Island (N.), 

 S. 59° W., 6.25 mi. (6° 44' 45" N., 121° 48' 00" E.), at a depth of 25 fathoms, in fine 

 sand. Type specimen, catalogue number 40913, United States National Museum. 



The female of this species is very similar to the female of Mga ommatophylax Steb- 

 binga but the male is entirely different from the male of that species. The female 

 of the present species is much larger than the female of Mga ommatophylax and has a 

 small V-shaped space in front of the eyes on the dorsal surface not shown in Stebbing's 

 figure. 



o Ceylon Pearl Oyster Fisheries Report, 1905, pt. IV, p. 21-23, pi. iv, v (A). 



