50 university of colorado studies 



Suborder Oniscoldea 



External antennae generally long, close together; body as a rule scarcely able to 

 be contracted in a ball; legs generally long; uropoda produced, reaching beyond 



the terminal segment of the abdomen Oniscidae. 



External antennae generally short; body able to be contracted into a ball; legs 

 generally short; uropoda short, not reaching beyond the terminal segment of the 

 abdomen Armadillididae. 



Family ONISCIDAE 

 The following key is based on that of Richardson: 



Flagellum of external antennae triarticulate I. 



Flagellum of external antennae particulate 2. 



1. Abdomen abruptly narrower than thorax .... Philoscia Latreille. 

 Abdomen not abruptly narrower than thorax; surface of body granulate or 



tuberculate; terminal segment of body conically produced 



Oniscus Linnaeus. 



2. Body very convex, capable of being rolled up into a ball; joints of flagellum of 



external antennae subequal; external opercular ramus of all the abdominal 



appendages furnished with tracheae .... Cylislicus Schnitzler. 

 Body more or less depressed, scarcely contractile; external opercular ramus of 



first and second pairs of abdominal appendages furnished with tracheae; 



second antennae long Porcellio Latreille. 



Metoponorthus Budde-Lund, found in Kansas and New Mexico, has the abdomen 

 abruptly narrower than thorax, and the flagellum of external antennae Particulate. 



(148) Cylisticus Schnitzler. C. convexus (DeGeer). Boulder, 1907 (C. DeVoss). 



(149) Porcellio Latreille. These common wood-lice must occur with us, but we have 

 no records. 



Miss Richardson thus separates the commoner species of Porcellio: 

 Surface of body smooth or minutely granular; second pair of antennae long, equal 

 to half the length of the body; color dark gray, with two longitudinal bands 



of a lighter color in wavy stripes P. laevis Latreille. 



Surface of body roughly granulate or tuberculate. 



Inner face of the mandibles with four to five pencils; color varying from gray 



to black, with three longitudinal lines of white spots P. rathkei Brandt. 



Inner face of right mandible with four to five pencils, of left mandible with 



seven to eight pencils; body without spots . . P. scaber Latreille. 



Family ARMADILLIDIDAE 



(150) Armadillidium Brandt. A. vulgare (Latreille). Greenhouse at Boulder, abundant, 

 January, 1911 (Warren E. Watkins). 



Order AMPHIPODA Latreille 



Body laterally compressed; branchial organs attached to the thoracic limbs. 

 Aquatic. Only one genus has been found in our region, but at Las Vegas Hot 

 Springs, New Mexico, in the hot water, I collected a species of Hyale Rathke, a 



