M. A. Giard on the Genus Entoniscus. 137 



with the posterior limb vertical and finely serrated. Dorsal 

 spines of moderate strength. Upper margin of the soft dorsal 

 eonvex ; dorsals continuous, but separated from each other by 

 a deep notch. Caudal emarginate; anal with long anterior 

 and short posterior rays. Upper and lateral parts dark olive- 

 coloured, each scale with two, three, or more whitish dots. A 

 black line along the hind margin of the praeoperculum. 



Of this species a gigantic example, 3 feet long, has been 

 sent by Herr Kubary from Ponape. The collector says that 

 it exceeds sometimes one metre in length, and that the natives 

 call it " KoiL" 



Sphcerodon euanus. 

 D. f&. A. fV L. lat. 51. L. transv. 5/17. 



Eye very large, one third the length of the head, equal 

 to the width of the interorbital space, and more than the 

 height of the prseorbital. Scales on the cheek in four series, 

 forming together a narrow vertical band. Dorsal spines rather 

 feeble, broader on one side than on the other, the longest 

 being a little shorter than the eye. The third anal spine much 

 longer than the second. The first ventral ray produced into 

 a filament. Coloration uniform, without any spots on the 

 vertical fins. Posterior half of the pectoral fin light-coloured; 

 base of the pectoral without black. 



One specimen, 13 inches long, from Eua, Friendly 

 Islands. 



XVII. — Notes towards the History of the Genus Entoniscus. 

 By A. Giard*. 



[Plate X.J 



I. Historical. 



Almost all the zoologists who have studied the parasitic 

 Cirripedcs belonging to the group Suctoria have been induced 

 also to pay attention to certain Isopod Crustacea of the family 

 Bopyrida3, the history of which is intimately bound up with 

 that of those animals. This was my own case when, in 1873, 

 I commenced my researches upon Sacculina carcini. In fact 

 this parasite itself bears a parasite, Cryptoniscus larvccformis, 

 upon which I have already published some preliminary re- 



* Translated bv W. S. Pallas, F.L.K., from the ' Journal de F Anato- 

 mic et Physiologic' L878, pp, t'-7- r j 700. 



