ISOPODS OF NORTH AMERICA. ()03 



square, extending the greater part of their length beyond the terminal 

 segment. The external branch is inserted at the inner post-lateral 

 angle of the basal joint and extends downward. The internal branch 

 extends much beyond the last abdominal segment, is longer than the 

 basal joint of the uropoda, and reaches the tip of the external branch. 



Color reddish-brown with markings of yellow. 



Four specimens were taken by Dr. C. W. Richmond at El Yunque, 

 Porto Rico, at an altitude of 2,800 feet. 



Type. Cat. No. 23914, U.S.N.M. 



SPHjERONISCUS CACAHUAMILPENSIS (Bilimek). 



Armadillo cacahuamilpemis BILIMEK, Verb, zool.-bot. Ges. Wien, XVII, 1867, 

 pp. 907-908. BUDDE-LUND, Crust, Isopoda Terrestria, 1885, p. 40. 



Locality. Cave in Cacahuamilpa, Mexico. Found under stones. 



Budde-Lund suggests that this form certainly differs from Oubaris 

 oecause the flagellum of the second antenna3 is composed of three arti- 

 cles, according to Bilimek. He suggests that perhaps it is nearer to 

 PseiidarmadUlo. Inasmuch as the species of PseudarniadUlo recently 

 described, and which undoubtedly belong to that genus, have but two 

 articles to the flagellum of the second antenna?, Bilirnek's species must 

 be referred to the genus Sphs&roniscus^ which is the only genus of 

 Armadillididse, having the flagellum composed of three joints. 



Body grayish brown, slightly rugose transversely, head transversely 

 dilated, with the anterior margin raised; first thoracic segment very 

 wide, with a lateral lobe similar to a tooth; last segment of the abdo- 

 men strongly constricted in the middle; uropoda narrow, twice as long 

 as wide. 



Grayish brown and covered with delicate little transverse ruga?. 

 Head very broad, three times as broad as it is long, anterior border 

 turned up broadly, but diminishing in breadth on the sides under the 

 eyes and especially behind. Antenna 5-jointed, with a 3-jointed flagel- 

 lum; eyes composed of 14 ocelli. First thoracic segment strongly 

 arched, broadest in the middle, and edged by a delicate border; a tooth- 

 like lobe is formed on the sides anteriorly, in front of \vhich there is 

 found a concave depression; on the back there is a flat transverse depres- 

 sion. Second segment about one-third narrower; the anterior portion 

 is depressed transversely by the overly ing anterior segment; the epim- 

 eron, which becomes narrower on the sides, is rounded and turned 

 straight downward. Segments 3 to 7 similar, with the exception that the 

 epimera on the side appears to be more bluntly cut off. First abdominal 

 segment quite narrow; it does not reach to the outer edge; second- 

 fourth continue to decrease in breadth and have a horseshoe-shaped 

 appearance; the fifth is bordered with two lateral lobes and is as long 

 as it is broad at the base; it is strongly constricted in the middle and 

 somewhat enlarged toward the outer border. The legs are 5-jointed, 



