ISOPODS OF NORTH AMERICA. 595 



Color of the dorsal surface reddish or dark gray, the frontal lobes, 

 especially the middle one, and a longitudinal band on the thorax 

 darker and covered with veiy numerous paler oblong spots. a 



ALLONISCUS CORNUTUS Budde-Lund. 



Alloniscus cornutus BUDDE-LUND, Crust. Isop. Terrestria, 1885, pp. 228-229. 

 RICHARDSON, Proc. U. S. Nat. Mus., XXI, 1899, p. 864; Ann. Mag. Nat. 

 Hist. (7), IV, 1899, p. 332; American Naturalist, XXXIV, 1900, p. 305. 



Locality. California. 



Body short, oval, subconvex, obscurely but densely roughened and 

 thickly punctate and setigerous. Second pair of antennae shorter than 

 half the length of the body (7:17); flagellum shorter than the fifth 

 article of the peduncle; the second article of the flagellum shortest, 

 the first equal in length to the third. 



Antero-lateral processes large, narrow, prominent, subconical; front 

 in the middle very much swollen. 



The first three segments of the thorax have the posterior nlargin on 

 both sides slightly sinuated; all the following segments have the poste- 

 rior margin in the middle rather sinuated posteriorly. 



The above description is adapted from the following one of Stuxberg's: 



Rhinoryctes-ovalis, longitudine duplo majore quam latitudine, convexus, densis- 

 sime granulatus, epimeris margine serratis. 



Antennae exteriores corporis latitudine multo breviores ( = 85:100); pedunculi 

 articulus quintus longissimus, parum curvatus, longitudine flagellum 3 : articulatum 

 sequans; flagelli articuli inter se eadem longitudine vel medius interdum minimus. 



Oculi, ocellis congregatis, prominentes, subcirculares. 



Lobus frontalis medius magnus, productus, obtusus, sursum porrectus, quartern 

 partem latitudinis capitis sequans; lobi laterales producti, conici, antice rotundati, 

 longitudine oculos sequantes. 



Trunci segmenta omnia rnargine postico medio sinuata. Epimera mediocria, 

 angulis anticis post sensim magis rotundatis, serratis, angulis posticis parum retro- 

 versis, rotundate-acuminatis. 



Cauda subcircularis, latitudine paullo majore quam longitudine, omnium seg- 

 mentorum longitudine sequali, epimeris segmentorum primi et secundi evanescenti- 

 bus, tertii, quarti, quinti maximis, retroversis, margine exteriore rotundatis, serratis, 

 interiore fere rectis. Segmentum ultimum trigonum, duplo latius quam longius, 

 marginibus posticis rectis, rotundate-acuminatum, supra convexiusculum et inter- 

 dum fovea longitudinal! haud profunda instructum. 



Pedum ultimi paris articulus basalis fere seque latus ac longus, depressus, margine 

 postico-laterali parum elevato, circulariter rotundato, serrato, appendix exterior 

 paullum complanata, subconica, margine exteriore recto, interiore convexo, longi- 

 tudine appendicem interiorem haud multo superans, quee ultimum caudse segmentum 

 parum excedit. 



Color dorsi rufo-vel fusco-griseus, lobis frontal! bus, pnesertim medio, vittaque 

 trunci longitudinal! nigrioribus, maculis oblongis numerosissimis pallidioribus 

 inspersis. 



Longitudo, 10 mm.; latitude, 4.5-5 mm.; altitudo, 2.3-2.5 mm. STUXBERG, 0fvers. 

 Vet. Akad. Forhandl., 1875, No. 2, p. 51. 



