No. 399.] WORTH-AMERICAN INVERTEBRATES. 229 
extremity ; terminal portion of segment obliquely truncated, the 
oblique portion being surrounded by a raised margin. 
Cleantis planicauda Benedict, G 
^ Flagellum composed of three joints. Abdomen composed of three seg- 
ments. Terminal abdominal segment with acute post-lateral teeth on 
either side of rounded posterior portion. Surface of segment smooth 
throughout. eec ap Cleantis heathii Richardson, 
FAMILY XIV. ARCTURID/E. 
Fourth segment of thorax not greatly longer than others. Marsupium 
of female composed of four pairs of plates. Arcturus Latreille 
Fourth segment of thorax much longer than any of the others. Marsu- 
pium of female consisting of two plates affixed to this segment. 
Astacilla Fleming 
A 
A 
ET 
Fic. 11. — Arcturus intermedius. 
Cenus Arcturus Latreille 
a. End of terminal abdominal segment notched, as seen from above. 
b. Body smooth and free from spines. 
Arcturus beringanus Benedict, A, 29-36 fms. 
V. Body spiny. 
c. Head and six segments of thorax, each with a pair of spines 
on the dorsum. Second and third articles of the antenna 
without spines. Arcturus longispinis Benedict, A, 55 fms. 
