MACRURA. - SCIIMITT. .>71 



groove ends below the posterior end of the accessory 

 rostral carina, one-third the distance from the level of 

 the hepatic spine to the rostral crest above. 



Dorsally the rostrum is armed with eleven teeth, of 

 which the first four are on the carapace, while the fifth 

 has its base above the posterior margin of the orbit. The 

 first tooth is about the size of the sixth, and the second 

 is intermediate in size between the fourth and fifth. 

 Anterior to the third, and largest tooth, the dorsal 

 rostral teeth gradually decrease in size to the last one, 

 which is about two-sevenths the length of the free portion 

 of the rostrum removed from the tip. The rostrum 

 extends as far forward as the spine of the antennal scale, 

 a little in advance of the last segment of the antennular 

 peduncle. The antennular flagella are shorter than their 

 peduncle, but longer than the last two joints, being as 

 long as the second, third, and about half the first joint 

 taken together. 



The petasmae of this species, P. pIcltcJHK, and P. 

 Jatisulcatus, are very much alike, and Kishinouye's 

 figure of the petasma of the latter would do quite well 

 for either of the other two. There is enough variation 

 in the size of the median protuberances in each of these 

 species, no doubt in direct ratio to the age of any par- 

 ticular specimen, to render it impossible to separate 

 them on the basis of this character alone. However, the 

 carination of the rostrum and the character of the lateral 

 sulci will always serve to differentiate them. 



Except for the peculiar crossing over of the lateral 

 grooves on the carapace, the male of P. maccuHoclii might 

 be mistaken for the male of P. plelcjus. As in the 

 latter, the last three somites of the abdomen are sharply 

 carinated. 



Measurmcnts. From the tip of the rostrum to the 

 end of the telson the holotype measures 155 mm. in 

 lengih ; the carapace and rostrum together equal 58 mm., 

 and the abdomen and telson 97 mm. ; the free portion of 

 the rostrum, 21 mm., and the telson alone 23 mm. The 

 spine of the antennal scale is 23 mm. long and falls 2-5 

 mm. short of the extremity of the blade. The third legs 

 are about 50 mm. long, and fail to reach the tip of the 

 antennal scale by about 10 mm. 



