1922.] 



S. Kemp : Notes on Crustacea Decapoda. 



227 



maxilliped is often broadened, the second peraeopods are heavily 

 bnilt with the distal end of the merus flattened or hollowed beneath 

 to accommodate the carpus when the limb is folded, and the last 

 three peraeopods are stout, without spinules on the propodus and 

 with a simple strongly hooked dactylus. The combination of these 

 characters gives the species a very distinct facies, though a parallel 

 to each may be found in the genus Periclimenes. 



Most if not all the species of the genus are found in associa- 

 tion with corals and there can be little doubt that they are speci- 

 ally adapted to life in this environment : the depressed form and 

 stout legs with hooked dactyl i are obviously well suited to an 

 existence among the branching stems of a madrepore colony. In 

 general appearance Harpilius bears a close resemblance to Corallio- 

 caris, the species of which are found in similar situations. 



CO. 



Text-iig. 66. — Second maxilliped of Harpilius Ititescens, Dana. 



a. As shown by Dana. 



b. With some of the errors corrected. 



Tattersall has already questioned the validity of the genus 

 Harpiliopsis and I endorse all that he has said. Borradaile's 

 reasons for establishing the. new genus are indeed remarkable. 

 Apart from the supposed absence of the arthrobranch on the 

 third maxilliped in Harpilius, the difference between this genus 

 and Harpiliopsis lies in the form of the second maxilliped. Of 

 Harpilius Borradaile has seen no specimens and his description of 

 the appendage is derived from Dana's fig. 4/ of H. lutescens. In 

 his generic description of Harpilius he says " second maxilliped .... 

 with last joint posterior to preceding joint" and adds that 

 the second maxilliped of the type Harpilius is so remarkable that 

 no species which does not share this peculiarity can be retained in 

 the genus." 



It is, of course, evident at first sight that Dana's figure is 

 erroneous and that the narrowly triangular terminal segment, 



