AMMOTHEA. ARACHNIDES. 203 



N. gracile, Leach. Cinereous ; thighs cylindrical. Inhabits Brit- 

 ish seas. Common. Zool. Mis. i. pi. 19, fig. 1. 



N. femoratum, Leach. Reddish ; thighs dilated and compressed. 

 Inhabits coasts of Devonshire. Zool. Mis. i. pi. 19, fig. 2. 



Gen. 2. AMMOTHEA, Leach. 



Mandibles much shorter than the rostrum, with equal joints, 

 the fingers arcuate, and meeting at their tips ; palpi nine- 

 jointed, the third joint very long ; legs slender ; thighs with 

 the middle joint longest ; claws double, unequal ; egg-bear- 

 ing organs nine-jointed, under the first pair of legs, behind 

 the rostrum. 



A. Caroliniensis, Leach. Body entirely brown, testaceous ; back 

 with three trigonate tubercles. Inhabits seas about Southern Ca- 

 rolina. Zool. Mis. i. pi. 13. 



Gen. 3. PHOXICHILUS, Lat. Phalangium, Mont. 



Legs very slender ; thighs with the middle joint longest, sub- 

 clavate; tarsi with the first joint very small ; claws double, 

 unequal, the longer one acute; egg-bearing organs seven-joint- 

 ed, the last joint tuberculiform, inserted at the base of the ros- 

 trum, one on each side, and attached to the first segment of 

 the body. 



P. hirsulus, Lat. (P. hirsutttm, Mont.) Lin. Trans, ix.pl. 5, fig. 7- 

 Gen. 4. PYCNOGONON, Lat. Fab. 



Legs rather strong ; thighs with subequal joints ; tibiae with 

 the first joint largest ; tarsi with the first joint very small ; 

 claws simple, strong, acute ; egg-bearing organs ten-jointed, 

 the last joint very acute unguiform, at the base of the rostrum. 



P. Balcenarum, Lat. Inhabits European seas. Lat. Gen. i. 144. 



FAMILY II. PSEUDOSCORPIONES. 



Palpi very large, pediform, either terminated by a didactyle hand 

 or by a vesicular button, without hook. 



The animals of this family have two spiracles ; but are destitute of the pediform 

 appendages for carrying the ova. The abdomen occupies a great part of the body, 

 which is generally oval or rounded, and not jointed. 



Gen. 5. OBISIUM, Illiger, Leach. 



Body cylindrical ; thorax composed of one segment ; mandibles 

 porrect ; eyes four. 



O. trombidioides, Leach, Second joint of the arms elongate ; fin- 

 gers long and straight. Inhabits France and England, under 

 stones. Sup. Encyc. Brit. i. pi. 23. 



Gen. 6. CHELIFER, Geoff. 



Thorax composed of three feet ; mandibles short ; eyes two. 

 C.fasciatus, Leach. Hands oval ; segments of the abdomen border- 



