36 



DR. G. S. BRADY ON THE 



long, slender, only moderately curved, and not at all crenulated, the outer blade having 

 a markedly constricted median neck ; outer branch of the left foot devoid of marginal 

 setae, simple, and terminating in two very small apical setae. Length 1"6 millim. 



Hab. Taken in the surface-net at Port Chalmers and in Otago Harbour. 



This may perhaps be the form referred to by Dr. Kramer as Centropages typicus, 

 var. aucklandicus, though in some respects it does not agree accurately with his figures 

 and description. It cannot, I think, be properly referred to any variety of C. typicus, 

 though the pectinated armature of the male right antennule agrees exactly with that 

 species. To make my meaning clearer I give some of the more important characters 

 of the two species in a tabular form. 



It is, however, very closely allied to C. brachiatus (Dana), and the females of the two 

 species may not be easily distinguishable, but the armature of the antennule, together 

 with the structure of the fifth pair of feet in the male, presents very sufficient distinctive 

 characters. 



Basal joints of the antennules 



15th and 16th joints of the 

 right male antennule. 



First abdominal somite in 

 female. 



Caudal segments in female . 



Prehensile branch of right fifth 

 foot in male. 



C. typicus. 



First, second, and fifth joints in 

 both sexes have strong mar- 

 ginal spines. 



Sixteenth joint has a strong 

 spine. 1 



Two slender spine-like setae on 

 ventral and a shorter one on 

 dorsal aspect. 



Twice as long as broad ; setae 

 not swollen at base. 



Inner claw slightly pectinated ; 

 outer not distinctly con- 

 stricted in middle. 



C. discaudatus. 



No well-developed spines on the 

 basal joints in either sex. 



A strong spine on both joints. 



One dorsal seta. 



Scarcely longer than broad ; 

 setae swollen at base. 



Inner claw not pectinated ; 

 outer distinctly constricted. 



2. Centropages pectinatus, sp. nov. (Plate IX. figs. 24-27.) 



Female. — Abdomen slender, four-jointed (figs. 20, 27), the first joint wider than 

 the rest, bearing on its dorsal surface a brush of several fine hairs and at the posterior 

 angle a single slender spine ; caudal segments about thrice as long as broad, two or 

 three of the principal terminal seta? dilated basally (fig. 27 b). Lateral spines of the 

 outer branches of the swimming-feet lancet-shaped, with very finely pectinated margins ; 

 median joint of the outer branch of the fifth pair (fig. 25) produced internally into a 



1 Giesbrecht figures a rather feeble spine also on the fifteenth joint, but I have not been able to find it in 

 any of my specimens. 



