708 T. R. R. STEBBING. 



The head is smooth, the telsonic segment is broadly rounded, not at all apically truncate 

 dorsally sprinkled with setiform spines, which seem to be less stiff than those in the other 

 species and not arranged in the same order. Round the apical border the armature was for 

 the most part worn away, but in the young there are six spines with intervening setae 

 just as in L. gardineri. 



The first antennae have a five-jointed flagellum, its first joint much the longest, the last 

 two minute, as is the case in the young taken from the marsupium. 



The second antennae are not specially robust ; the flagellum is thirteen-jointed. 



The mouth-organs do not give much assistance, because as shown in the figure the first 

 maxilla of the young one is normal, as was also the case with a larger juvenile specimen 

 not taken from the pouch of the mother, but this organ in the mother itself has a comparatively 

 short terminal hook and a short oval inner plate. This form of the first maxilla is probably 

 therefore a casual abnormality. The maxillipeds are very short, with the vibratory plate of 

 the second joint extending to the top of the sixth joint. In the maxillipeds of the juvenile 

 specimens there is nothing to show that the shortness of these appendages is abnormal, but 

 as they are without the vibratory plate of the female comparison is not easy. 



The peraeopods are rather more slender than in L. gardineri. 



Length 5"25 mm., by a breadth of 2 ram. There were also two small specimens, each 

 under 3 mm. long. 



Locality. Mahlosmadulu Atoll, taken along with Lanocira gardinen at 20 fathoms. 



L. kroyeri, Hansen, the type species of the genus, from Rio Janeiro, among other differences 

 has only four spines on the apical margin of the telsonic segment. 



Gen. Alcirona, Hansen. 



Alcirona, 1890, Hansen, Vid. Selsk. Skr., Ser. 6, Vol. v. Pt. 3, pp. 285, 313, 391; 1893, 

 Stebbing, History of Crustacea, p. 346. 



This genus is well characterized by the very broadly crescentic epistome, the elongate 

 peduncle of the second antennae, and the two-spined apex of the first maxillae. 



To the two species for which it was instituted by Hansen, a third is now added. The 

 three may be distinguished as follows : 



(Hinder part of body remarkably setose. 1. A, krebsii, Hansen. 



(Hinder part of body very moderately setose. — 2. 



(First gnathopods with robustly pectinate finger. 2. A. insidaris, Hansen. 



[First gnathopods with the finger simple. 3. A. maldivensis, n. sp. 



7. Alcirona maldivensis, n. sp. PI. LI B. 



The head is smooth, with a rather blunt rostral point. At the centre of the back the 

 fourth segment of the peraeon is nearly as long as the first, and the seventh not much shorter 

 than the fourth. The first two segments of the pleon are much concealed, the first, however, 

 though very short at the middle is not at that part obsolete as in the species of Lanocira 

 here described. The angles of the fourth segment are strongly produced, outflanking the 

 rounded slightly produced corners of the fifth segment. The telsonic segment has the sides 



