FRESH-WATER CRUSTACEA. 841 



A few specimens of this species were taken in the river Tigris at Ama- a It 

 is evidently closely allied to C. diaphanus, Fischer-Claus, but is readily distin- 

 guished from it and from other species by the form of the fifth feet and of the 

 furca and receptaculum seminis. It resembes most nearly Ciiclops pnnamenftis 

 Marsh, the fifth feet of which have an almost identical shape", but it differs irl 

 size, general form of body and other details. 



Cnnthocamptus staphylinus, Jurine. 



A few specimens of this species, agreeing in all respects with the typical form 

 were taken at Ezra's Tomb, Mesopotamia, and at Resht, N. W. Persia. The 

 collections were made in February and March respectively. This is a northern 

 cold-water form, which largely disappears in summer in Europe, and its 

 occurrence under the climatic conditions of Mesopotamia is somewhat unex 

 pected and remarkable. 



Diaptomus vulgaris, Schmeil. 



Common at Ezra's Tomb : a single male taken at Enzeli, N. Persia. The speci- 

 men from Ezra's Tomb agree in every detail with the typical form as described by 

 Schmeil with the following exceptions : the antennae slightly exceed the lent^th 

 of the body ; the second basal joint of the left fifth foot of the male bears a 

 single narrow hyaline process ; the last thoracic segment of the female is slightly 

 asymmetrical. The species is distributed almost all over Europe, and a number 

 of races or elementary species have been described from south-east Europe. Its 

 occurrence in Mesopotamia and N. W. Persia is of interest as considerably ex- 

 tending its known range. 



Diaptomus blanci, Guerne & Richard. 



Amara, in irrigation runnels. 



Originally described from Turkestan, this species has since been recorded from 

 Central Asia, Aral Sea and from India. 



Diaptomus chevreuxi, Guerne and Richard. 



Female : — Cephalothorax almost parallel-sided, the width about one-third 

 of the length. Last segment incompletely separated, with rather large, sym- 

 metrical, posterior lobes. Rostral filaments rudimentary. Abdomen slightly 

 exceeding half the length of the cephalothorax and consisting of four segments ; 

 the first, or genital, segment very short and scarcely dilated, without any trace 

 of lateral spines, but with a large flattened, dorsal expansion on the right side. 

 Furcal rami rather long and narrow, the width less than half the length, the 

 inner side without cilia. 



First antennae reaching, when fully reflexed, to the posterior edge of the first 

 abdominal segment. 



Fifth pair of legs without hyaline processes on basal segments or on first 

 segment of exopodite. Endopodite one jointed, about two-thirds of the length 

 of the first joint of the exopodite, bearing two short spines of unequal length 

 at its apex. Second joint of exopodite short and broad, with an unusually short 

 strong claw, denticulate on the side. Third joint absent, its place being taken 

 by a thick, bent, spine, at the base of which is a short denticle. 



Length 3 • 3 mm. 



Four females of this species were found in a collection from a dike beside 

 an ancient causeway at Gantra Sarut on the left bank of the R. Tigris between 

 Amara and Ali Gharbi. 



Dr. Buxton noted that the species, when aUve, was of a scarlet colour. 



This species has only been recorded hitherto from Algeria and its occurrence 

 in Mesopotamia is a matter of some interest as it is apparently absent from 

 intermediate countries such as Egypt where it might be expected to occur. 

 In Algeria it is found 'n ditches and other temporary waters, and the con- 

 ditions in Egypt would seem to be entirely suitable. Three of the specimens 



