ORDER PffiCILOPODA. 367 



have at their base a strong hook, toothless and recurved ; while 

 the inferior are of four articulations, with a small tooth to the 

 first. The siphon is directed forwards. The feet are twelve in 

 number; the first two terminate bj a basement, annulated, 

 transversely, widened circularly at the end, striated and den- 

 ticulated on its edges, presenting at the interior a sort of 

 rosette, formed by the muscles, and appearing to act in the 

 manner of a cupping-glass, or sucker. Those of the follow- 

 ing pair are adapted for prehension, with the thighs thick 

 and spinous, and the tarsi composed of three articulations, 

 the last of which is provided with two hooks. The other 

 feet are terminated by a fin, formed of two fingers or 

 elongated pinnulae, furnished on their edges with barbed 

 filaments ; the first two of these, that is, the thii'd pair, 

 comprehending the two preceding pairs, have each an addi- 

 tional finger, but recurved ; the last two are annexed to that 

 portion of the body which projects posteriorly out of the testa, 

 i. e. the tail. The females have but a single oviduct, and 

 covered by two small feet, situated behind these two palettes ; 

 the organ considered as the penis of the male, is placed at the 

 internal extremity of the first articulation of the same feet, 

 near the origin of the two digits. On the same articulation 

 of the two preceding feet, and facing these copulative 

 organs, is a vesicle presumed to be seminal. The abdomen, 

 considering as such that part of the body which extends 

 behind from the ambulatory feet, the beak, and a tubercle 

 enclosing the heart, is entirely free, from its origin, without 

 distinct articulations, and is terminated immediately after the 

 last two feet, by a sort of tail, lamelliform, rounded, deeply 

 emarginated, or bilobate, and without hairs at the end. It 

 is a sort of fin. The transparence of the body allows the heart 

 to be distinguished; it is situated behind the base of the siphon, 

 lodged in a solid tubercle, semi-transparent, and formed of a 

 single ventricle. The blood, composed of small transparent 



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