262 BOPYRIM. 



or neck with the hind part or matrix, which is exarticulate or sacciform, 

 kidney-shaped, destitute of appendages. 



Length of male, one-tenth of inch ; female, (?) 



Liriope pyymcea. H. RATHKE, Reise Bemerk. aus Skand. in Neust. 



Schr. Naturf. Ges. Danzig, torn. 2, p. 105110 

 (1841). Nova Acta Acad. Cses. Leop. Nat. 

 Curios, torn. 20, p. 244, pi. 1, figs. 812. 

 LILLJEBORG, Liriope et Peltogaster, in Nova Acta 

 Reg. Soc. Upsal. ser. 3, vol. iii. p.. 6, pi. 1, figs. 

 123 (1859). Suppl. to ditto in ditto, pi. 6, 

 figs. 1, 2 (1860). 



Oniscus squiUifonnis. PALLAS, Spec. Zool. fasc. 9, p. 50 ? CAVOLINI, 



Mernoria sulla Generaz. dei Pisci e dei Granchi, 

 transl. Erzeugung derFische u.d. Krebse, pp.164, 

 165, pi. 2, figs. 18 m, n, r, r. 



THE history of this species has been remarkable, nor 

 can it yet be regarded as free from difficulties. Cavolini, 

 as quoted above, first described and figured two different 

 crustaceous animals (one of which he doubtingly referred 

 to the Oniscus squilliformis of Pallas) which he had 

 found parasitic within a sac attached to the tail of a crab 

 belonging to the genus Portunus or Carcinus. In 1839, 

 Rathke found in the Norwegian Sea, upon the bodies of 

 Carcinus mcenas and Pagurus Bernhardus, two species of 

 vermiform parasites, which he regarded as belonging to 

 the Entozoaria (but which have since been proved, by 

 their transformations, to belong to the Cirrhipeda), and 

 which have subsequently been described under the names 

 of Pachybdella Carcini * and Peltogaster Paguri. 



Within the body of the latter of these two parasites 

 Rathke found eight minute crustaceans, which he con- 

 sidered had been devoured by the Peltogaster, and which 

 he described under the name of Liriope pygm&a, referring 

 them to the order Amphipoda, unaware that the generic 



~ Professor Bell, in his volume on the Stalk-eyed Crustacea, p. 108, de- 

 scribes the female of this parasite (Packybdella carcini) as infesting Por- 

 tunus marmoreus even to a greater extent than Carcinus mcenas. 



