586 SUMMAKY OF CURRENT RESEARCHES RELATING TO 



out life. In aiitotomously severed rays, growth coDtinuee, especially at 

 the proximal end where new rays soon begin to appear, radiating out 

 from a new mouth. Rays severed at some distance from the disk give 

 rise to new disks and rays just as well as those which separate close to 

 the disk. Autotomy in this starfish is not merely a normal process 

 originated by internal stimuli, but is an asexual method of reproduction 

 of prime importance. 



Interesting New Ophiuroid.* — H. Matusomoto describes Astro- 

 pJiiura kawamurai sp. n., in which the free arms are only 6 mm. in 

 length and only 0'4 mm. in breadth close to the pentagonal body. 

 The free distal parts are very abortive, being devoid of any dorsal and 

 ventral arm-plates as well as tentacle pores. In some radii, indications 

 are not wanting of the first free arm-joint being in the process of incor- 

 poration into the pentagonal body. The new form is compared with 

 the genotype A. permira Sladen, and with Chun's Astropliiura. which 

 has not been specifically named. 



Coelentera. 



New British Commensal Hydroid.t — James Ritchie reports from 

 Irish waters the occurrence of Perigonimiis abi/ssi Sars. It is symbiotic 

 with living molluscs, forming a network on the external surface of the 

 shells. Apart from examples observed by Sars on DentaUum, it has been 

 reported only on minute shells of Nuculidae. The " blistered " state of 

 the shell of Leda (now Niwulana) pustulosa, to which Gwyn Jeffreys 

 referred, is due to Perigonimus ahyssi. The polyps are exceedingly 

 small — almost invisible to the naked eye. The stolons form a network 

 on the shell. Previous records have been from the Indian Ocean. 



Athecate Hydroid with a Leptomedusoid.J — E. Stechow describes 

 a small colony of athecate hydroids, which he names Oampanopsis dubia 

 sp. n. There is a conical hypostome, a whorl of 14-18 tentacles, an 

 unbranched hydrocaulus with distinct periderm, a reticulate hydrorhiza, 

 The hydranths are spindle-shaped when contracted, with a deep sub- 

 tentacular neck when expanded, and there is no trace of a theca. The 

 genus Gampanopsis should probably be referred to the base of the 

 Halecidae. The medusa from which the colony is believed to have 

 originated belongs to the genus Octorchis ( = Eutima). 



Protozoa. 



Gypsina plana. § — Marjorie Lindsay describes this fixed encrusting 

 Foraminifer from the Indian Ocean, which spreads over any kind of 

 decayed calcareous matter. It grows to an extraordinary size (e.g. 

 3-4 in. in diameter of the widest part of the encrustation). The in- 

 dividual chambers are also large. The surface is marked into clearly 

 defined areola, about 120 /^ in diameter and with the walls of each 



* Annot. Zool. Japon., viii. (1913) pp. 225-8 (1 pi.). 



t Sci. Invest. Fisheries Ireland, 1913, No. 1, pp. 1-3 (1 fig.). 



: Zool. Anzeig., xli. (1913) pp. 582-6 (1 fig.). 



§ Trans. Linn. Soc. (Zool.) xvi. (1913) pp. 45-51 (6 figs.). 



