90 Dr. W. Bairtl on British Entomostraca. 



Latreille, Hist, des Crust. 207 ; Lamarck, An. sans Vert. v. 128. 

 no. 3. — Chydorus Mullen, Leach, Sup. Enc. Brit. art. Crustacea ; 

 Diet, des Sc. Nat. xiv. 541. — Monoc. sphsericus, Jurine, Hist, des 

 Mon. 1. 16. f. 3. — Lyn. sphsericus, Desmarest, Cons, des Crust. 377 ; 

 Baird, Trans. Berw. Nat. Club, p. 100 ; M. Edwards, Hist, des Crust. 

 iii. 386 ; Pritchard, Micros. Cab. t. 8. f. 3.* 



Shell round, smooth, slightly ciliated on anterior margin; 

 of an olive colour. Rami very short ; anterior branch has 

 three setae springing from the extremity of last articulation, 

 and one from extremity of second f ; posterior branch has only- 

 three from last joint. Intestine convoluted, having one com- 

 plete convolution and about a half. Tail jointed, and having 

 two stout claws at its extremity ; the intestine passing through 

 the joint and terminating in the anus near the claws. Eye 

 areolar, its accompanying black spot pretty large and situated 

 just above the root of the antennae. Its motion through the 

 water is more like rolling, as Jurine describes it, than swim* 

 ming. The mandibles, feet and antennae are very like those 

 of the preceding subgenus. According to Pritchard, "the 

 young play near their parent, and at the approach of danger 

 swim for protection within the shell of the mother, which she, 

 conscious of their feebleness, immediately closes % ! !" 



Hab. Ponds and ditches. Common. 



2nd Sp. Chydorus globosus. PL III. fig. 1 — 4. 



Shell quite globular, a good deal resembling in form the 

 last species, but more completely rounded and nearly six times 

 larger ; striated circularly on exterior and upper margin, and 

 dotted with small black spots ; the anterior portion of shell is 

 reddish coloured, with a large irregular-shaped dark band 

 running across the centre of shell and occupying about half 

 its extent. The beak is extremely long, and at times appears 

 to lie close to the body. Tail elbowed at the joint and hol- 

 lowed out immediately before it, terminating in two long 

 claws. Eye large, areolar. Intestine convoluted, having one 

 complete turn and about a half. First pair of feet large. An- 

 tennae large, with seven teeth and seven long setae§. Rami very 

 short and slender. Anterior branch has four setae, one from 

 second articulation and three from last. Posterior branch has 

 three only from last joint. The motion of this species is very 

 much like that of a Cypris. 



Hab. Ditch near Richmond ; pond near Isleworth. Rare, 

 apparently confined to small patches. 



* In Koch's ' Deutschlands Crustaceen,' &c. there is a figure of the Lynceus 

 splmricus, Heft 8. t. 2. ? but it is certainly not the L. sphcericus of Miiller. 

 f PI. II. fig. 13. % I. c. p. 90. 



§ PI. III. fig. 2. 



