ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 441 



From the structure and mode of articulation of the first antennae, 

 the author considers that they are not functionally locomotor, but 

 rather tactile organs ; although in the allied genera Cypris, Cypridinn, 

 and Halocypris, these appendages are used for swimming. The second 

 antenna consists of four joints, and is bent upon itself; this is the 

 chief swimming appendage, since the legs are used chiefly, if not 

 entirely, for walking on the mud at the bottom of the water ; on the 

 third joint is a small papilla, probably an olfactory organ. Kising 

 from the base of the second joint is the flagellum or " sting," of some 

 authors, which is characteristic of the family ; it is usually said to be in 

 connection with a poison-gland, but although in an allied genus Sclera- 

 cMIus, the author was able to find a gland with a duct opening at the 

 distal extremity of the flagellum, he was unable to find either gland 

 or duct in any of the eight species of Cyfhere examined for the pur- 

 pose. The use of the flagellum is obscure. As an organ of defence 

 it appears useless, since the shell, thick-coated in C. jonesii with 

 carbonate of lime raised in knobs, closes upon tlie slightest touch, and 

 is itself a sufficient protection from preying animals. It may have 

 something to do with obtaining food ; in those Ostrocoda which live 

 on the remains of other water-animals, this flagellum is stunted and 

 therefore is of no use as a means of catching or killing prey, even 

 if the food had to be obtained by such means. The author is at 

 present unable to ofier a solution on this point. The mandible 

 consists of a biting portion, and a tactile portion or palp carry- 

 ing on its outer side a small branchial portion. The maxilla is 

 chiefly a branchial lamella, with a small portion in relation to the 

 mouth. 



The copulatory apparatus of the male is of extraordinary size and 

 of great complexity. Essentially it consists of a " basal plate," or 

 rather a triangular and quadrangular plate fused, resting on each side 

 of the abdomen. The posterior, upper angle is drawn out into a 

 sharp spine. Articulating with the anterior lower part of this basal 

 plate, is the organ which serves to clasp the abdomen of the female. 

 This " clasping plate " is roughly an elongated triangular plate, the 

 posterior lower angle of which is produced so as to form a sharp, 

 slightly hooked process, characteristic of C. jonesii. At the articula- 

 tion of this clasping plate with the basal plate is a medley of chitinous 

 bands and knobs, serving for copulation ; at the apex of one of the 

 spines is the opening for the vas deferens, and it is this spine which 

 is inserted into the vagina of the female. In the female there are 

 two pairs of openings in the posterior of the abdomen ; of these the 

 hinder pair are the apertures of the two oviducts, whilst the other 

 two pores are the " vaginae," and lead into a canal in communication 

 with the seminal vesicle. 



After describing C. jonesii, the author gives a shorter description 

 of C. antiquata and C. quadridentata. 



In Sclerochilus contortus a gland and duct are found at the base of 

 the second antenna. The copulatory organ is uncoloured, and the 

 " clasping plate " is relatively much smaller than the " basal plate." 



Ser. 2.— Vol. VI. 2 G 



