DR. W. M. TATTERSALL : A5IPHIP0DA AND ISOPODA. 5 
outer plate are serrate on both margins, a feature not, so far as I aware, 
described in Pontliarpinia. 
1 am quite unable to understand Stebbing's descrij^tion of the second 
gnathopod unless, indeed, by some chance the descriptions of gnatliopods 
1 and 2 have become inadvertently transposed in his diagnosis. As will be 
seen from the figures of these appendages given here, the fifth joint is 
decidedly lai'ger in gnathopod 1 than in gnathopod 2, and with this sup- 
position, Stebbing's description of the giiathopods would a|>ply to my 
specimen. 
Stebbing's description is based on specimens from New Zealand recorded 
by Thomson (1882) as Plioxus batei, Haswell. Stebbing identifies Thomson's 
specimens with Phoxus viUosus, Haswell, and refers Haswell's P. batei to 
Pontharpinia roslrata (Uana). On comparing my specimen with Thomson's 
description and figures, T find the most complete agreement exce})t that the 
carpus of the second gnathopods is distinctly shorter than Thomson shows. 
Thomson does not describe or figure the fourth perseopods. 
My specimen differs from Haswell's original description in the larger size 
of the eyes, in the fewer joints in the accessory appendage of antenna 1, and 
in the shape of the second joint of the fifth perseopods. In the characters of 
the eyes and the fiftli perseopods it agrees with Haswell's description of 
Phoxus batei, and as the latter is said by Haswell to diifer from P. villosus 
in the larger size of the eyes and the i'orm of the fifth perseopods, it looks as 
if my specimen really belonged to Phoxus batei, liasv.'e[\ — Pontharpinia 
rostrata (Dana). But the long and slender form of the fourth peraeopods 
agrees much more with those figured by Haswell for P. villosus. 
The genera Pontharpinia and Parharpinia are distinguished, according to 
the definitions of these genera given by Stebbing in ' Das Tierreich,' by the 
iollowing characters : — 
(1) In Pontharpinia the third joint of the mandibular palp is shorter 
than the second. In Parharpinia the third joint is longer than 
the second. 
(2) In Pontharpinia the outer plates of the maxillipeds are short. In 
Parharpinia they are elongate and fringed with serrate spines on 
the inner margins. 
(3) In Pontharpinia the fourth and fifth joints of the third and fourth 
perajopods are expanded. In Parliarpiniaihej m-q not expanded. 
(4) In Ponthai'pinia the expanded second joint of the fifth perseopods is 
greatly produced, while in Parharpinia it is only moderately 
jiroduced. 
These differences appear to me of doubtful value. My specimen is a 
Parharpinia in the characters of the mandibular palp and the form of the 
third and fourth perseopods, and a Pontharpinia in the characters of the 
maxillipeds and of the fifth perseopod. 
