340 "ENDEAVOUR" SCIENTIFIC RESULTS. 



rostrum, it being slightly longer and having fewer teeth 

 in n ovw-guinece" 



I have also been enabled to examine several 

 specimens of Haswell's "Penceus Palmoiisis" from the 

 Macleay Museum. Regarding these Mr. McCulloch 

 wrote, "I identify as this species a large female 29 mm. 

 long from tip of rostrum to end of carapace, together 

 with two smaller females and two small males, all from 

 Darnley Island, which are forwarded for examination. 

 These were confused with P. granulosus by Haswell, 

 and the notes upon the males at the end of his descrip- 

 tion of that species are based upon these specimens. 

 I have critically compared one of the smaller females, 

 11-5 mm. long from tip of rostrum to end of carapace, 

 with the holotype of P. palmcnsis, which is of about the 

 same size, and find it agrees in all details." 



In a brief key to the Peneids described by Haswell, 

 which the late Allan E. McCulloch was kind enough to 

 prepare for my convenience, he considered palmensis a 

 variety of novce-guinecB, but I feel certain that, together 

 with P. stridulans, they represent but one species. The 

 range of variation which was observed bv de Man in his 



V 



"Siboga" series of 23 males and 29 females is sufficient 

 to include the differences Haswell detected between his 

 novce-guiriece and pal men aim. In a survey of his material 

 de Man remarked: "The examination of these numerous 

 specimens, though mostly of young or of medium size, 

 proved that Pcna'opxis stridulans (W.-Mas.) is a very 

 variable species. At first, indeed, the specimens did 

 appear to me to belong to two different species, but the 

 existence of several transitional forms led me to the con- 

 clusion that all ought to be referred to one and the same 

 species. The variability bears upon the toothing of the 

 rostrum, the more or less distinct development of the 

 branchiostegal spine, the form of the stridulating organ 

 and the number of its ridges. 32 the shape of the carina on 

 the 3rd abdominal tergum, of the thelycum and of the 

 thoracic legs, as also the length of the telson." The 

 rostra of de Man's specimens carried from 5 or 6 to 8 



;2 For want, possibly, of sufficient specimens showing the short, 

 straight, high placed stridulating organ, and the longer, curved, lower 

 placed form, I have been unable to detect any noticeable or really 

 appreciable differences in the epimera of the first abdominal somites, 

 which play upon the several different types of stridulating organs in 

 this species 



