302 Dr. Philippi on the Hersilia apodiformis* 



shorter. In the tail on each side is the orifice for the female 

 sexual apparatus. 



What I could observe of the cibarian apparatus is as fol- 

 lows : Behind the tentacula are two diverging mandibles, 

 which are of the form of an obtuse-angled quadrant, and upon 

 the posterior side of the second joint it is beset with long and 

 thick cilia. Between their insertion is a triangular space with 

 the apex directed posteriorly, perhaps the mouth. Beneath 

 the cilia, on each side, are three maxilla, which terminate in 

 a forked bristle, and consequently remotely remind us of the 

 pincers of Limulus. In both sexes between these parts and 

 the first pair of feet is situated afoo t jaw on each side. It is 

 nearly quadrate, and terminates at the anterior and inner angle 

 in a long acute tooth : on the front side it also carries a small 

 appendage of a vesicular form, and exteriorly a biarticulated 

 flagelliform palpus. I could not distinctly recognise the sexual 

 apparatus of the male from the minuteness of the animal. Two 

 large almost clavate organs which were inserted in the vulva of 

 the female are situated on both sides of the mouth, besides 

 which there are two antenniform setigerous organs, which take 

 their origin close behind the true antennae. At first sight the 

 animal reminds us of Apus by its great shield, but it is more 

 nearly allied to Cyclops by its tail and the biramified legs. It 

 is still more nearly allied to the genus Sapphirina of Thom- 

 son, with which I am acquainted only from Lamarck's c Hist. 

 Nat. 5 (2nd edit. &c. vol. v. p. 171.)* which also has a flat com- 

 pressed shield-like body, biramified legs, and only two tenta- 

 cula, but is distinguished from it by a shield of nine seg- 

 ments and four pairs of biramified legs. The essential cha- 

 racters are briefly contained in the following description : 

 Corpus clypeo magno e segmentis quatuor formato obtectum. 

 Antennae duac magnae, filiformes, 5-articulatae. Pedum paria 

 quatuor, tria pinna bifida, quartum simplex. Cauda apice 

 bifida et setigera. 



Fig. 9. Hersilia apodiformis, mihi. A female lying on its back. Sixty times 

 magnified. 

 i. The eyes. 



a. The mandibulse ? 



b. The maxillas. 



c. The foot jaw with its biarticulated flagelliform palpus. 



d. The three pairs of biramified legs. 



