MORGAN HEBARD 141 



a median pair of slender spines with few spinulae near leases; 

 succeeding segments unarmed; auriform process of fifth less de- 

 cided than in female; sixth, seventh and eighth segments carinate 

 medio-longitudinally, with dorsal surface of carina rather broad 

 and flattened; seventh segment expanding laterad, the remaining 

 segments broadened so that the end of the abdomen is clubbed, 

 its caudal margin irregularly serrate, the supra-anal plate pro- 

 duced to a strongly bilobate apex, the inner faces of these adja- 

 cent lobes heavily denticulate. 



Measuroneiit-'i {in nnllinuiers) 



_-p\ Length of Length of Length of Length of Length of 



O body pronotum mesonotum metanotum'i caudal femur 



San Antonio 39.5 7.7 5.6 13.9 15.2 



San Antonio 37.5 7.7 5.5 14 15.7 



9 



San Antonio 43 8.4 6.1 12 15.7 



Acanthoclonia strangulata now species (Plate XX, figs. 1, 2 and 3.) 



This i'emarkul)le insect belongs to the forms of the genus show- 

 ing no laminate projections on head and other segments of the 

 body. The remarkable and very large pair of composite spines 

 on the mesonotimi show a transition from the type of the heavy 

 pair of spined plates, as fouiul in the species of the first section 

 of the genus, to the much smaller and less striking pair of sub- 

 composite spines, as found in the forms showing no laminate 

 projections on head and other body segments. 



It is noteworthy that, in apparently every species of Acan- 

 thoclonia, the position of plates and spines shows in some or many 

 features a distinctive arrangement from that found in any other 

 species. It is pro})able that the contrast between the sexes is a 

 matter largely of degree, as discussed und(;r A. erinaceus Red- 

 tenbacher. 



The elongate mesonotum, which is decidedly narrower cephalad 

 than caudad, and great iunnl)er of spines on the body, are striking 

 features in the present species. 



Type. — 9 ; San Lorenzo, Siena Nevada de Santa ^Vlarta, Mag- 

 dalena, Colombia. Elevation, 8300 feet. August 2)3, 1913. 

 (M. A. Carriker Jr.) [Hebard Collection, Type No. 451.] 



"' In the present paper the length of the metanotura, as given for the Phas- 

 niidae, inckides the median segment unless otherwise stated. 



TRANS. AM. ENT. SOC, XLV. 



