96 Rev. T. R. R. Stebbing on new Crustaceans. 



of sponges and gorgonias sent me by Mr. Wilson Saunders. 

 The Sphaeromid, shown in fig. 1, occurred in a collection from 

 Swan River, S.W. Australia ; the Arcturidae, figs. 2 and 3, 

 in one from Fort Elizabeth, Algoa Bay, South Africa. 

 Fig. 1 appears to be a Cymodocea • it has the setose tail and 

 tail-appendages of that genus, the tail-piece terminating in a 

 deep notch, occupied by a produced central plate or lobe. The 

 body is very convex, with the sides parallel ; the flagella of 

 both pairs of antennae are multiarticulate ; the branches of 

 the tail-appendages do not close one under the other. 



The species would be appropriately named Cymodocea tu- 

 berculosa ; for though the first segment of the pereion is smooth 

 and marbled, the five following segments are adorned and 

 almost covered with rows of shining tubercles. Tubercles 

 can be detected among the matted hairs of the pleon and uro- 

 poda ; and notably a row of three is conspicuous on the lobe 

 which runs out into the notch at the end of the tail-piece. 

 The branches of the uropoda have a pair of smooth shining 

 tips at the extremity of each. The head, which is nearly as 

 broad as the body, is long and sloping ; its frontal border has 

 two small nostril-like prominences in the centre ; a lower 

 frontal margin is adorned with ten teeth or turrets, divided 

 into two sets of five, and exhibiting between them a still 

 lower frontal plate with two shining lobes. The colour of the 

 mouth is red, of the claws brown. The length of the animal is 

 rather under half an inch ; but, in spite of the small size, the 

 beauty of the details makes it an object of considerable interest. 



Fig. 2 represents an animal of still more remarkable ap- 

 pearance, which pretty clearly belongs to the genus Arcturus 

 of Latreille, a genus described by Spence Bate and Westwood 

 as " remarkable among the Isopoda for its slender cylindrical 

 form, the length of its lower pair of antennae, and the delicate 

 ciliated structure of the four anterior pairs of legs, whilst the 

 hind ones are short and very robust." Our African species 

 agrees with all these details, except that the bulging character 

 of the fourth segment of the pereion is scarcely consistent 

 with such a description as " a slender cylindrical form." It 

 still seems an open question whether the British Arcturi ought 

 not to be separated from A. Baffini, the type of the genus, 

 which has the fourth segment of the body scarcely longer than 

 the others, and the lower antennas terminated by multiarticu- 

 late flagella. Were the genus Leacia or Leachia revived to 

 receive them, the species now under consideration would join 

 them in it, its fourth segment having a very conspicuous de- 

 velopment, and the lower antennae bearing three-jointed in- 

 curved flagella like those of our British species. Meanwhile 



