216 DR. W. T, CALMAN ON 



Jetties, 5 miles from river entrance in Moreton Bay, in Swamp 

 Mahogany (^Tristania saaveolens) and Ironbavk (Eucalyptus 

 paniculata). Many specimens. 



Specimens are in the Museum collection from Wyong River, 

 New South Wales, and Brisbane (Prof. Chilton), Travancore 

 (lYivandrum Mus.), Isipingo River, Natal (Durban Mus.), and 

 St. John's River, Palatka, Florida (U.S. Nat. Mus., syntypes of 

 S. destructor Richardson). 



Remarks. — This species has already been recorded from Bris- 

 bane by Prof. Chilton. 



Barnard has recently adduced further evidence in favour of 

 Stebbing's view, disputed by Miss Richardson, that the Indo- 

 Pacific species is identical with S. destructor Richardson, from 

 Florida, No one, however, has hitherto been able to base this 

 identification on a direct comparison of specimens. By the 

 courtesy of the authorities of the U.S. National Museum, who 

 have presented syntypes of S. destructor to the British Museum 

 (Nat. Hist.), I have been able to compare these with specimens 

 from all the other localities mentioned above. I have failed to 

 find any difference that can be regarded as specific. Both Stebbing 

 and Barnard have indicated a certain amount of variation in the 

 tubercles and ridges of the dorsal surface, and this is shown more 

 conspicuously by the specimens now examined. The specimens 

 from Brisbane grow to a greater size (11-5 mm. total length) 

 than the syntypes, and have the tubercles on the sixth and 

 seventh peraeon-segments very low ; the submedian tubercles on 

 the telsonic segment are distinctly elongated in an antero- 

 posterior direction, and the granulation of the telsonic segment 

 is less close than in the syntypes. The Travancore specimens 

 agree better with the syntypes in their smaller size, generally 

 more prominent tubercles, and closer granulation of the telson, 

 but they difter in having the submedian tubercles of the telson 

 distinctly smaller than those of the lateral pair. The Natal 

 specimen bears a close resemblance to those from Brisbane. I 

 have only been able to observe one character in which the Indo- 

 Pacific specimens agree with one another, while differing from 

 the syntypes. Seven specimens from Wyong River, Brisbane, 

 Travancore, and Natal were found, on dissection, to agree with 

 Stebbing's account in having three large seta3 and a small one on 

 the inner plate of the maxillula. Miss Richardson found in her 

 specimens " five strong plumose setje and occasionally a sixth one 

 that is feeble." The single syntype that I have dissected has five 

 large setse and a small one on the maxillula of one side, but on 

 its fellow there are six setfe of equal size. In none of the other 

 characters mentioned by Miss Richardson is there any constant 

 difference to be detected *. 



* S. periivianum Richardson (Proc. U.S. Nat. Mus. xxxviii. 1910, p. 81, text-figs. 

 3 and 4), found boring in the roots and stems of mangroves on the coatst of Peru, is 

 very similar to the species here discussed, but the broadly-rounded terminal segment, 

 the longer antennules and antennse, and other characters indicated by Miss Richard- 

 sgn may justify its separation. I have seen no specimens. 



