belonging to the Family LaodiceidEe. 475 



Genus Staurodiscus, Hseckel, 1879. 



Oeneric character. — Laodiceidaj with four main radial 

 canals, each with lateral branches. 



The two genera Staurodiscus and Toxorchis are distin- 

 guished from the other genera of the Laodiceidas by the 

 presence of branched radial canals. It was on account of the 

 branching of the canals that Hajckel placed these genera in 

 the Cannotidffl. Tiie Cannotidse, as a distinct family, has 

 now ceased to exist ; its destruction was due to a revision of 

 its genera by Maas (1904). Staurodiscus and Toxorchis 

 were transferred by ]\Iaa3 to the Berenicidse, to which he 

 gave an emended definition. 



Berenice is the type genus of the Berenicidse. One species 

 {B. rosea) is without marginal bulbs, but the other (^B. Hux- 

 ieyi) has bulbs. I am uncertain whether these bulbs are 

 cordyli or only tentacular bulbs ; if they should turn out to 

 be cordyli, then the species should be transferred to the genus 

 Staurodiscus. 



Staurodiscus tetrastauras, Hseckel, 1879. 



Staurodiscus tetrastaurus, Hfeckel, 1878, p. 145, Taf. ix. figs. 1-3 ; 



Mayer, 1900, p. 46, pis. xviii.-xix. figs. 47-49 ; JVIaas, 1904, p. 440. 

 Staurodiscus heterosceles, HaBckel, 1879, p. 146. 



In this species each of the radial canals has a pair of lateral 

 branches which do not join the circular canal. The gonads 

 develop upon the blind branches and also upon the portion of 

 the main canal between the branches and the circular canal. 

 There are eight to sixteen tentacles and two or three cordyli 

 between every two tentacles. Cirri absent. A black ocellus 

 at the base of all the tentacles and cordyli. Mayer describes 

 young stages as well as adult, and states that the ocelli are 

 endodermal. 



Distribution. North Atlantic : Canary Is. {Hcechel). 

 Tortugas {Mayer). 



Staurodiscus nigricans, Agassiz and Mayer, 1899, p. 164, 

 pi. iv. figs. 11-12. 



This species has radial canals with a pair of lateral branches, 

 which do join the circular canal. The gonads are upon the 

 branches and the portion of the main canal between the 

 branches and the circular canal. Twelve tentacles present 

 and six or seven cordyli between every two tentacles. Cirri 

 and ocelli absent. 



Distribution. Pacific Ocean ; Fiji {Agassis and Mayer) . 



31* 



