History of British Entomostraca. 325 



neck terminates by a horny acute point, under which are six small 

 teeth on the same plane. This horny point, Jurine thinks, replaces 

 in some degree the external mandibles, which in this species are 

 wanting ; and thus not having an organ by means of which to seize 

 its prey, it uses its antennules for that purpose, putting them into 

 rapid motion, causing a regular whirlpool in the water, which at- 

 tracts every object into its centre, where is situate the mouth. Be- 

 hind the mandibles, and a little lower, are two small round bodies, 

 almost transparent, which do not exist in the preceding species. 

 These two bodies, when the animal eats, separate from each other 

 so as to open a passage for the food, which is seen to pass through 

 the opening thus made. Jurine calls these the lips. They are fur- 

 nished with a barbillon (Fig. 4,) which consists of three parts, in- 

 ternal, middle, and external, all provided with hairs. Hands (Fig. 

 5,) different from those of quadricornis, each divided at their origin 

 into two distinct parts — anterior, smaller of two, may be called the 

 thumb, and is composed of three rings, the anterior edge of which 

 is rough with small eminences, from which spring a number of pret- 

 ty long hairs directed towards mouth ; the posterior part is much 

 larger, and consists of six rings, the two first very large in propor- 

 tion to the other four.* Feet (Fig. 6) are the same as in C. qua- 

 dricornis. Under the last segment of body in the male, we perceive 

 two stalks, almost cylindrical, both arising from one common base. 

 (Fig. 7-) The rightone consists of five segments, and is terminated by 

 a strong hook ; the left one has only four rings, and is shorter. These 

 bodies are considered as the sexual organs by Jurine, the shorter of the 

 two stalks containing, he believes, the organ itself, f In same situa- 

 tion, in the female, we find the fulcra or "supports" (Fig. 8) which 

 Muller calls " uncinuli," and which are of a very irregular shape ; 

 and underneath the first ring of tail is the vulva, through which also 

 the eggs pass intoexternal ovaries. Above the vulva we see a triangu- 

 lar reddish body, which Jurine calls operculum vulvae. In some spe- 

 cimens of this species, we occasionally see on each side of the tail, 

 two, four, or six elongated bodies, the direction of which is always 

 backwards. In females, they are found adhering round the opercu- 

 lum vulvae by a long and slender petiole, from which issues a sort of 

 demi-capsule, which Jurine compares to an acorn. From this en- 

 velope springs a cylindric transparent body, which shows in its in- 

 terior a longitudinal opaque line. These are what Muller calls the 

 lacinice, which he regards as some particular organs belonging to the 



* These organs, the hands, are what Muller describes under the name of la- 

 mince radiatce. 



f These are the " Spicula duo curva" of Midler. 

 no. iv. y 



