408 EEV. T. E. E. STEBBING ON AMPHIPODA FEOM 



apex ; the sixth in the iirst pair is shorter than the fifth, but in the second at least as 

 long, in both narrow, oblong, narrowest at the base, with tlie short palm transverse or 

 slightly tending to form an acute angle with the hind margin. 



Perceopods. The fourth pair are rather longer than the third, and the fifth than the 

 fourth. In the third and fourth pairs the second joint is oval, in the fifth pair it is 

 much wider, with flattened front and very convex hind margin. There are accessory 

 brancbifc to all the five pairs. The ordinary brancbias were not perceived on the fifth 

 pair. 



TJropods. These are unusitally slender. The first and second pairs have lateral spines 

 on both rami. The third pair are comparatively long, the tapering ramus rather longer 

 than the peduncle, and extending considerably beyond the telson. 



Tel son. Oblong oval, with a pair of spinules on the rovmded apex. 



Length. A fifth to a quarter of an inch, 5-6 mm. 



Hab. Laguno di Espino. Sjiecitnens belonging to the Copenhagen Museum, obtained 

 by Dr. Meinert, in compliment to whom the species is named. 



In regard to the first and second antennae this species agrees closely with Faxon's 

 " Allorchestes dentatus, var. ffracilicornis," and in other respects with his " Allorchestes 

 longistilus " ; but for neither of these forms is any mention made of accessory branchiae, 

 nor do those appendages appear to be present in Hyalella iiiermis S. I. Smith, to which 

 Faxon's species are closely related. 



Chiltonia, n. g. 



First four pairs of side-plates deep. First and second antennae equal in length. First 

 maxillae without palp, although distinctly notched at the palp's usual position. Maxil- 

 lipeds with the fourth joint of the palp small, conical. Other mouth-i^arts as in the 

 family character. First and second gnathopods sulichelate, the second differing greatly 

 in the two sexes. The third uropods one-jointed. Telson simple. 



Name of the genus given in compliment to Dr. Charles Chilton, M.D., D.Sc, F.L.S. 



Chiltonia mihiwaka (Chilton). 



1898. Hyalella mihiwaka Chiltou, Annals and Magazine of Natural History, ser. 7, vol. i. p. 423, pi. 18. 



The typical species has been very accurately described and figured by Dr. Chilton, 

 who has obliged me with specimens. It seems possible that the pear-shaped third 

 uropods may represent a peduncle and ramus coalesced into a single joint. 



" Colour. Greyish or nearly white. 



" Size. Largest specimens about one-fifth of an inch (5 mm.). 



" Hah. Mountain -streams near Port Chalmers, up to about 1500 feet above sea-level 

 {Chilton). In hillside stream at East Taieri ; from spongy moss at top of Mount 

 Cargill, 2200 feet, and on Swampy Hill, 2400 feet {G. 31. Thomson)." 



