BELONGING TO DAPHNIA AND OTHER ALLIED GENEEA. 



245 



Fig. D. 

 Moina rectirostris. 



1. Female seen from right side x 28. 



2. Antennule X -Jo. 



3. Post-Atidomen x 105. 



rounded angles ; the head much narrower and separated by a 

 constricted neck, rounded off in front and below and sinuous 



dorsally. Antennules simple, 

 fusiform (fig. D2), with a few 

 small terminal sensory fila- 

 ments and a single long hair 

 near the middle of the anterior 

 margin. Antennae similar to 

 those of Daphnia but having 

 a single short spine, in addition 

 to the natatory setae, at the ex- 

 tremity of each branch. Post- 

 abdomen (fig. D 3) slender^ 

 narrow, gently tapered to the 

 extremity, and ending in a 

 long, curved unguis; marginal 

 setae twelve, conical, subequal, 

 and delicately plumose ; base of 

 the unguis bearing a pectinate series of about fourteen fine cilia, 

 no abdominal processes. Shell ciliated on the ventral margin, 

 granular, with spots of pigment (?) irregularly scattered near 

 the margins, more or less distinctly reticulated towards the poste- 

 rior dorsal angle. Length, 1*4 mm. 



The male I have not seen, but it is described by Dr. Baird and 

 other authors as differing from the female much in the same way 

 as the sexes differ in Daphnia. 



Dr. Baird found this species in "a pond upon Blackheath, 

 October, 1849." I have myself only once met with it, in a pond 

 on Walton Common, near Brampton, Cumberland, July, 1897. 

 Mr. Scourfield has taken it at "the Isle of "Wight, JSTorfolk, 

 Surrey, and in Epping Forest," and Dr. ITorman has specimens 

 taken by Mrs. Tupper Carey at Ebbesburne, near Salisbury. 



A second species, M. hrachiata, is recorded by Dr. Baird from 

 the Blackheath pond and from " a stagnant pool in Old St. Pan- 

 eras Eoad," which has since been built over. 



