Sliiilir^ iHi riiMi-ini' Oslracoils 1 (O 



a pDWcrlul. tdicc-jointed clasping organ. The end joint in tlic tcmale — and also in the males 

 ill which this l)nmcli is not developed as a clasping organ — is always furnished with (inly 

 one bristle; this bristle is fixed at or near the point of the joint, often attains a rather consi- 

 derable length, is finely annulated. naked and more or less rounded distally (a sensory bristle?). 

 In the inales in which this branch is developed as a clasping organ this joint is furnished with 

 a similar bristle, fixed ventrally, near the proximal boundary of the joint (homologous with 

 the bristle in the female?) and most frequently with a few (always two?) short distal bristles, 

 placed close together. . 



Mandible: — With or without sexual dimorphism. — The p r o t o p o d i t e 

 joints, like the two proximal endopodite joints, are always comparatively large and 

 powerful, the end joint of the endopodite is, on the other hand, very small. P r o t o- 

 p o d i t e: The endite of the coxale is most frequently (always? cf. below in connection with 

 the description of the males of the genus Philomedes) developed in both males and females, 

 small but rather powerfully built, not lamelliform and hyaline, simple or more or less bifurcated 

 distaUv. Basale: Has no well-developed endite proximally-ventrally-medially but, on tlie 

 other hand, always or almost always traces of one in the form of a number of bristles. This 

 joint always has two bristles dorso-distally. The exopodite is always developed, always 

 has two most often rather long bristles situated ventero-distally and always the openings of 

 a large gland. The endopodite is three-jointed, its end joint has practically always 

 seven bristles. 



Maxilla: — Cf. fig. Ill, p. 32. With or without sexual dimorphism. — In most 

 cases it is developed as a masticatory organ, short and powerful, with strong musculature. 

 The males of the sub-family Philomedinae are exceptions, in them this limb is very weak and 

 certainly not used for mastication of food. It consists of a powerful, thick but rather short 

 p r o t o p o d i t e with three joints, a rather large and strong, two-jointed endopodite 

 and a more or less reduced, weak and unjointed exopodite. Between the coxale and the 

 basale this limb forms a ventrally open knee. Protopodite: All the three joints are 

 generally well defined and moveably joined with each other; procoxale and coxale are most 

 frequently rather large, basale is rather small or of moderate size. It is not furnished 

 ventrally with numerous long bristles arranged in a row like the plates of baleen of a baleen 

 whale (as in the family Asteropiclae). The procoxale and coxale are armed with three, in excep- 

 tional cases ( PseudofhUomedes) with only two, large, powerful masticatory processes, fitted 

 distaUy with powerful bristles. In the males of the sub-family Philomedinae these endites are 

 rather large, but nevertheless extremely weak, cf. above. The masticatory processes aie 

 Hattened, situated with their flat sides pressed rather closely against one another, overlap each 

 other a little, and are somewhat turned outwards in relation to the longitudinal axis of the 

 limb. When the maxilla is in a position of rest, i. e. pointing obliquely forward and outward 

 the endites point about straight out to the sides, in other words they are placed about trans- 

 versaUy to the longitudinal axis of the bodv. (Their position may perhaps best be illustrated 

 by means of the annexed diagrammatic drawing, representing a horizontal section through 

 this limb.) The basale is without traces of an endite. The exopod ite is furnished with 



