182 TAOE SKOGSBERO 



all species, is illustrated by the t'ollovviiig figures (taken from measurements of Ci/pridina 

 (DuluriaJ lecis, $): 



Pr. I I; Tr. II "^^ End. I J ; End. II |; End. Ill | . 

 Protopodite: Coxale: The endite is always well developed in both males and 

 females, simple or usually weakly bifurcated distally, sometimes, as, for instance in the genus 

 Crossophorus, even rather deeply bifurcated*; it is fitttxl with a varying, generally very large, 

 number of smooth spines, varying in strength and manner of arrangement; in the cases when 

 it is bifurcated distally the two distal points are almost always armed with lateral spines. 

 [ExcejDtion among the species seen by me: Monopia (Cypridinodes) acumi'naia]. Dorsally at the 

 base of the endite there is, in addition, (always?; observed in all the species of this sub-family de- 

 scribed in this treatise) a single, short bristle. Apart from this this joint seems always to be 

 entirelv without bristles (with the exception of the genus Crossophorus, see G. S. Brafa', 1880, 

 pi. XXXVIII, fig. 6). Basale: The bristles on this joint are certainly subject to variation both 

 as to their number and development, but, as far as I have found, the variation is, in most forms, 

 rather insignificant. Along the ventral side of the joint the bristles are comparatively few in 

 number, usually about six to nine, in exceptional cases, as, for instance, in the genus Crosso- 

 phorus, somewhat more. The situation of these bristles in the species examined by me was 

 pretty constant and as follows: One group is placed in the proximo-ventral corner of the joint, 

 somewhat medially; somewhat distally of this group and somewhat laterally, there is often a 

 single bristle; a little proximally of the middle of the joint there are a couple of bristles and some- 

 what distally of this point a couple more. Dorsally this joint seems in most cases to have only 

 three bristles, viz. the two dorso-distal bristles which are, as is pointed out above, characteristic 

 of the whole family and another one, placed about at the middle of the joint or a little in front 

 of this point. In the genus Crossophorus, however, the latter bristle is replaced by a whole 

 series of rather long and powerful bristles. Exopodite: Most frequently about as long 

 as or very slightly shorter or longer than the anterior side of the first endopodite joint; it is 

 drawn out to a rather fine point and has dorso-distally a sort of cushion of rather short, exceedingly 

 fine hairs placed closely together in a ring (exits of the glandular cells). E n d o p o d i t e: 



■" In a number of forms, in which this eiulile is only \vt'al<.ly bifurcati'd, for inslanie in Cypndina (Cypridina) 

 fserrata var. ajfirmans (cf. below, fig. 9 of this form), there is between the two distal points a more or less well- 

 developed spine-shaped or verruciform process. In other forms, in which this endite is more deejily bifurcated, this process 

 is entirely absent. To judge from its situation, this process may possibly be interpreted as the original point of the 

 endite. The two comparatively powerful (loinls on each side of the process in cimslion would a<'cording to this point 

 of view be considered as having presumably arisen by two of the distal sjiines with which the endite is more or less copiously 

 fm-nishcd liaving developed more powei'fuUy than the others. According to tliis (i]ii:iion this cnilite originally would 

 havi' been iharacterized by a simple point in lliis gronji of animals. 



There an' also, however, fads that seem to argue against this inlev]irelalion. I''irsl this endite is deeply 

 bifureated in I'/ulonii'dinae, Sarsiellidap and Asleropidae, thus in all the remaining groups of Cypridinifnrincf in which 

 it is developed, and secondly it is most deeply bifurcalt^d (about the same as in Philomcdinae] in that genus of the 

 sub-family Ci/pnilininar (Crossophorus) whirh we have rather strong reasons to regard as the most primitive. An 

 additional argument against the assum|jlion that the two distal ])oinls are to be regarded as a couple of spines seems to 

 nie 1(1 lie in tlie fact that tliese points, even in species in which they are comparatively weakly developed, are almost 

 always armed witli secondary spines conti'ary to the nther spines of this endite wliicli are all jierfeclly smooth (exception: 

 Monopia (Ci/pridinodcs) acuminoln). 



It may. however, be imi)0ssiliU: at pr'eseni to decide with certainty which of these two allernatives is the correct one. 



