136 
Walter M. Tattersall, 
( Apex of the telson armed with 3 pairs of strong piumose 
^ J spines 6 
I Apex of the telson armed with 5 pairs of rather short simple 
l spines P. théeli Ohlin 
Lateral margins of the telson armed with 13 — 14 spines 
P. calloplura H. & T. 
Lateral margins of the telson armed with 5 spines 
P. parvum Vanhöffen 
f Lateral margins of the telson nnarmed . . P. nanum H. & T. 
* \ Lateral margins of the telson armed with more or fewer spines 8 
Ocular plates smooth, without armature, antennal scale not 
extending beyond the antennular peduncle, telson armed 
with 6 spines on each margin P kruppi sp. n. 
Ocular plates with 12 teeth on the antero-lateral corner, an- 
tennal scale far outreaching the antennular peduncle, telson 
armed with about 30 spines on each margin . P. keììipi H. & T. 
21. MysidopsiSf sp.? 
M. gibbosa, Lo Bianco (1903). 
The single specimen, a female 7 mm in length, which is referred 
to M. gibbosa O. 0. Sars, by Lo Bianco, deviates somewhat from 
the fìgures given by Sars (1870 — 79) in the characters of the telson 
and uropods. 
The telson has the lateral margins considerably more concave 
than is shown in Sars' figure so that the form in dorsal view is 
somewhat narrowly lanceolate. The number of spines on the lateral 
margins is only 10 and they only extend about five-sixths of the 
way down instead of almost to the apex as shown in Sars' figure. 
The outer uropod is considerably narrower than shown by Sars 
while the inner uropod extends half way between the apex of the 
telson and the tip of the outer uropod and has only one spine on 
the inner ventral margin. 
Having only one specimen at my command from the Mediter- 
ranean, I am unable to say whether these slight differences indicate 
a new but closely allied species or whether they are due to ab- 
normality. In other characters the specimen conforms to Sars' figures, 
but I prefer to leave the species to which it should be referred, 
an open question for the present. 
