266 S. I. Smith — Tropical and Suh-ti'ojncal 



structure, with large outer and small inner lamellae. The uropods 

 are smallj with a very short base, and a single broad ov^al lamella 

 which reaches only a little beyond the tip of the telson. 



When the megalops is at rest, the abdomen is curved beneath the 

 body, and the chelipeds and ambulatory legs are folded very com- 

 pactly beneath the carapax. 



The specimens examined were all taken at the surface of the water 

 in the evening, August 26 and 27, and September 2, 1875. 



Polyonyx macrOCheleS Stimpson (ex Gibbes). 



Mr. Faxon (Bull Mus. Comp. Zool., Cambridge, v, p. 256, 1879) 

 states that the adult of this species has been detected once, by Alex- 

 ander Agassiz, under stones on the shore at Newport, R. I. Mr. 

 Faxon also says: on several warm days in August, 1878, the zoese of 

 Porcellana [P. inacrocheles] swarmed in the streaks of smooth water 

 on the edge of the tidal currents at the mouth of Narragansett Bay." 

 Alexander Agassiz had previously observed the zoea of this species 

 at Newport (Proc. Boston Soc. Nat. Hist., x, p. 222, 1866). I have 

 never observed any stage of the species in Vineyard Sound or else- 

 where on the New England coast. The adult appears to be not 

 uncommon as far north as Beaufort, North Carolina. 



Petrolisthes armatus Stimpson (ex Gibbes). A small specimen of 

 this species was found in a bottle with other invertebrata collected, 

 by Prof. Verrill and a party of students, at Stony Creek, on Long 

 Island Sound, near New Haven, in the autumn of 1867 or 1868. At 

 the time it was brought in, I suspected, without any good reason, 

 that a stray specimen had been accidentally taken out on the excur- 

 sion in one of the bottles and, in this way, got mixed with the speci- 

 mens collected ; but now I have little doubt that it was an erratic 

 specimen from much further south. As far as I am aware, the spe- 

 cies is otherwise not known north of Florida and the Bermudas. 



Latreutes ensiferus stimpson (ex M.-Edwards). 



Several small specimens of this Gulf Stream species were taken at 

 the surface in Vineyard Sound, during August and September, 1875. 



