64 

 FaM-: SrilAERO.MIDAE- 



1840. '■'■ Spheronu'ens,^' Milne-Edwards, Hist. Nat., Crust., 

 vol. 3, p. 197. 



!847- ^'pliacroniidae, White. List of Crusitacea in P.rit. AIus., p. 

 102. 



1900. Sphacroinidac, Stebbini;-, Proc. Zool- Soc London, p- 552. 



1901. Sphacromidac. Harriet Richardson, Proc. U.S. Mus-, vol- 



23- P- 532. 



1902. Sphaerofnidac, Harriet Richardson, Trans. Connect. 



Xcad, Sci., vol. 1 1, p. 291. 



In the Proc. Zool Soc. London for 1900 a list of authorities on 

 this family is given^ and it is scarcely necessary to repeat it here. 



Gen. : ExosiMiAEROMA, Stabbing. 



3900. Exosphaero)/ia, Stebbing, Proc. Zool. Soc. London, 

 P- 553. 



EXOSPHAEROMA AMPI.IFKONS, n. Sp. 

 Pl..\TE II. 



The head, which is slightly notched at the summit, is remark- 

 able for the wall-like steepness with which it rises in front far 

 above the eyes- A small triangular rostrum separates the cavi- 

 ties from which spring the bases of the first antennae, and, on 

 €Uher side of these a small wing or hollowed surface of the head 

 lies below the greatly projecting eye-lobes. 



The peraeon is broad, strongly imbricated, a deep cavity being 

 formed by the dorsal slope of the first segment and the postero- 

 dorsal slope of the head. The side-plates of the last six segments 

 are rather abruptly bent downwards and even a litde inward, the 

 last thi ntling less acutely than the prtneding three. The 

 infero-lateral margin of the first segment forms an acute angle at 

 either end, in front hel])ing to embed the eye-lobe, behind slightly 

 under-riding the side-]:)late of the second segment. A very 

 notable peculiarity of the species is furnished by the eroded 

 appe 'r ( f caused by little pits in the intesjument. These are 

 conspicuous on the lower part of the liead and its adjoining 

 appendages, over much of the first peraeon segment, on all the 

 side-plates and hind margins, and over a great part of the pleon- 

 In the last three ])eraeon segments the hind margins are cut into 

 several blunt denticles, of which there are two, not always very 

 ■distinct, on each of the three preceding segments. 



