

20 



rostral prominences. Eyes and ocellus wholly absent. Frontal tentacle, how- 

 ever, well developed, terminating, as a rule, in a more or less distinctly defined 

 club-like dilatation. Anterior antennae in female rather feeble and apparently 

 immobile, carrying on the tip a fascicle of delicate sensory filaments, in male, 

 as a rule, much more fully developed and freely mobile. Posterior antennae 

 powerfully developed and not essentially different in structure from those in 

 the Cypridinidae, inner ramus comparatively small, biarticulate, with the proximal 

 joint bulbously dilated, the distal one small and tipped with a fascicle of sen- 

 sory setae, being in male moreover armed with an abruptly curved hook. An- 

 terior lip more or less produced in front; posterior lip well marked, bilobed. 

 Mandibles with the body well chitinised, wedge-formed, and terminating below 

 in a complicated masticatory part; palp, as in the Cypridinidae, large, subpedi- 

 form, and abruptly bent in the middle, but without any distinctly defined 

 exopodal appendage, its 1st joint produced at the base below to a toothed 

 lobe adjoining the masticatory part of the mandibles. Maxillae built on the 

 very same type as in the more normal Cypridinidae, though having the outer 

 2 masticatory lobes coalesced. The 3 succeeding pairs of limbs more deviating 

 in structure and more or less pediform, the anterior pair being however sub- 

 servient to mastication, and thus more properly termed maxillipeds; last 

 pair very small, not vermiform. 2 pairs of trilobate vibratory plates present, 

 attached to the bases of the maxillipeds and the anterior legs, the latter limbs 

 more or less transformed in male. Caudal lamellae more or less rounded in 

 shape, with one of the claws inserted to a ledge of the anterior edge and 

 more slender than the others. Copulatory appendage of male single, sinistral. 

 Ripe ova, as a rule, not received within the cavity of the shell (sole exception 

 Euconchoecia). 



Remarks. The present family is a very sharply defined one, exhibiting 

 some apparently rather essential differences from the Cypridinidce, though 

 evidently belonging to the same chief division. The proposal set forth by 

 Dr. Skogsberg, to remowe this family wholly from the Myodocopa as a distinct 

 suborder, I am quite unable to approve. In my opinion the 2 families Cypri* 

 din idee and Conchoeciidce form together a very well defined and quite natural 

 group of Ostracoda, to which alone the systematic rank of a true suborder 

 can be assigned. Indeed, I think it may clearly appear from the diagnosis 

 given above of the Myodocopa, that all the fundamental characters by which 

 this suborder distinguishes itself from any of the 3 other suborders here recorded, 

 are equally well applicable to the Conchoeciidce as to the Cypridinidce. As I 

 am of opinion, that the several families in which the Cypridinidce has been 



