ENTOMOSTRACA FROM CEYLON. 127 
If we exclude those species which are found both in Ceylon and 
in more than one other region*—that is, the widely distributed 
species—the numbers are as follows :— 
Palearctic a5 a He 1 
Nearctic er ve axe — 
Neotropical ais an «is — 
Ethiopian ae ee eM — 
Australian ae as ie — 
Indé-Malayan Sub-region 
i 
The single species found only in the Palearctic Region and in Ceylon 
is Chydorus ovalis, Kurz. It was recorded by Poppe and Mrazek, 
but they expressed some doubt as to its identity with the European 
species. Seeing that the genus Chydorus is peculiarly rich in Orien- 
tal species, differing but little one from another, this record cannot 
carry much weight. 
From the figures given above it is evident that the Entomostracan 
fauna of Ceylon contains a large proportion of peculiar forms, and 
that, of the remainder, those that are limited to a single region 
are all Indo-Malayan species. There is no doubt therefore that 
there is a close relationship between the fauna of Ceylon and Indo- 
Malaya, but it is not safe to speculate on relationships with regions 
lying further afield. 
Through the kindness of Dr. Willey I have recently received 
specimens of a Diaptomus and a Streptocephalus collected in Ceylon, 
and it is further evidence of the richness and peculiarity of the fauna 
that both species prove to be undescribed. They were collected by 
Mr. E. E. Green in a muddy stagnant pool on the Cotton Experiment 
Station at Maha Ilupalama in the North-Central Province of Ceylon 
when looking for Mosquito larve. 
The following is a description of these species :— 
Order : PHYLLOPODA. 
Streptocephalus spinifer, n.sp. (Plate I.) 
The body in both sexes is somewhat slender, the head and thorax 
together a little longer than the abdomen without the caudal rami ; 
the following are the measurements of three specimens :— 
Female. Male. 
: LT. 
Head and thorax... 5°25mm. .. 4° 5mm... 5. 5mm. 
Abdomen io) (oe Olimmde a? Tbe. ifs. 6.7 OF mms: 
Caudal rami jee Onna arb nammoie B2aib mim. 
Egg sac eee TT. 2 Sma te, = 
Total length (2225 mim... 9°15 mm.» ...13°25,10m. 

* For the purposes of this comparison I consider Ceylon as a region by 
itself, distinct from the rest of the Oriental Region. 
s 10(4)06 
