142 



I'AGE SKOOSBERO 



Stage, these lengths vary somewliat. The seventh limb is of the definitive type with 



two distal bristles, one long and one short one. The number of bristles on the other limbs 



is (iiilv very slightlv decreased. The penis consists of two very small embryonal processes. 



Each f u r c a 1 lamella has six claws, 

 which decrease fairly regularly in linigth 

 and strength the more proximally they 

 an' situated. 



Female: Shell: Average length, 

 1,00 mm. It is of the same type as in 

 the male of this stage; the secondary teeth 

 on the postero-dorsal spine are, however, 

 somewhat less developed. The r o d- 

 shaped organ is similar to that of 

 the male in this stage. The limbs are 

 about the same as in the female of the 

 preceding stage. The f u r c a is similar 

 to that of the male in this stage. 



There cannot be the slightest doubt 

 that these two larval stages really belong 

 to C. elegans, as in the region from which 

 these specimens were obtained there are, 

 except the species mentioned, only two 

 forms of the genus Conchoecia, namely 

 C. ohtusata G. 0. Sars and C. borealis 

 G. 0. Sars; there is no risk of confusion 

 with either of these species during the 

 two oldest larval stages. 



It seems also to be quite certain 

 that they represent two moults. The 

 agreement with the observations of 

 C. Clau.S and G. W. MUller is com- 

 plete; cf. the latter author, 1894, 

 pp. 183. 184. 



M e a s u r e in e n t s: — 

 258 specimens of this species from 

 the station mentioned were investigated 



and measured. The measurements of the lengths of the shells gave the following result, as 



shown graphically in fig. XXII. 



The above table shows that tlie specimens could be divided into three distinct male 



and three female classes according to the lengths of their shells. The male class 58 — 61 and the 



female 5.3 — 60 represent mature specimens. 



IcT 



/? 



i<r 



Fif^. XXII. — Curves showing the n'sultsol' my iiK'asurenienls dI' 

 thcli'iiKths of the sliells of a mmiher of specimens of Cnnchnecid 

 (■/■■^aiis from Koster. west cdast of Sweden. — = the female.s; 



= the males. Tlie abscissa represents the lengths nf 



the shells expressed in divisions of a micrometer (27 divisioiiN 

 =^ 1 mm.): the ordinate represents llie nmnliei' dt sjieeinnMis 



measm'ed. 



