Ptdi palpi from the Lower Amazons. 359 



The young are much more variegated in colour than the 

 adults, the terga of the abdomen being ornamented with a 

 pair of pale spots, which converge and become united upon 

 tlie seventh segment. 



Genus Heterophrynus, Poc. 

 fleterophrynus longicornis (Butler). 



Fhripnis longicornis, Butler, Aqu. & Mag. Nat. Hist. (4) xii. p. 123 



(1873). 

 HeterophrynuH loiigicornis, Pocock, Ann. & Mag. Nat. Hist. (6) xiv. 



p. 287 (1894). 



Several specimens of this species were obtained under tiles 

 and bricks at Par^, others in termites' nests in the forest at 

 Santarem, and one at Monte Alegre. It has been previously 

 recorded from the two first-mentioned localities. 



The only comment that it seems necessary to make in 

 connexion with these specimens is that the shortness of the 

 chela or palp in the male, which I pointed out as distinctive 

 of this form as compared with chiracardhus and Batesii, 

 though regarded as of no importance by Dr. Kraepelin, seems 

 to be a perfectly constant, and therefore important, character. 

 In Batesii and cMracanthus the femur of the chela is about 

 twice the width of the carapace in length, whereas in longi- 

 cornis the length of the chela only just exceeds the width of 

 the carapace in the adult and is much less than the length of 

 the femur of the second leg, instead of being approximately 

 equal to it or greater than it, as in cMracanthus or Batesii. 

 It is true that the chelee are much shorter in the young than 

 in the adult, but that the shortness of the organ in longicornis 

 is not attributable to youth seems proved by the circumstance 

 that it obtains in the largest specimens examined — specimens 

 with the cara})ace attaining a width of 16-18 millim., the 

 femur of the palp being but 19-20 millim., whereas in 

 examples of Batesii with the carapace 12*5 millim. in width 

 the femur of the appendage in question measures 25 millim. 

 In an ovigerous female of longicornis from Pard, with the 

 carapace 15 millim. wide, the femur of the chela measures 

 14*5 millim. 



Family Thelyphonidae. 



Genus Thelyphonellu.s, Poc. 



Thelyphonellus amazonicus (Butler). 



Thelyphonus amazo7i{cuXy Butlt^r, Ann. it Mag. Nat. Hist. (4) x. p. '_'()!, 



phxiii. tig. 2 (1872). 

 Thehjphonellun omozo/iicns, Pococli, Ann. & Mag. Nat. Hist. (0) xiv. 



p. i;W 1894j. 



26* 



