996 SUMMARY OF CURRENT RESEARCHES RELATING TO 



He regards, that is, Balanoglossus as the last representative of a 

 group which had Chordatc, but not Vertebrate ancestors ; the Lam- 

 preys, Lancelots, and Ascidians are, like it, degenerate types. 



Littoral Fauna of the Channel Islands.* — M. E. Kohler gives a 

 list of the animals which he collected at Jersey, Guernsey, Herm, and 

 Sark ; at Herm the most interesting form was Balanoylossus sarniensis, 

 which is described as being long and fairly stout ; its body is so soft 

 that a complete example was never obtained. It seems to be about 

 35 cm. long, and at the collar is about 1 cm. broad. The conical pro- 

 boscis is of a bright yellow colour, the branchio-genital region is deep 

 orange, and the hepatic green ; the terminal portion of the body is 

 colourless. Behind the collar the dorsal surface is rather deeply 

 excavated ; there are forty hepatic caeca, which are simple diverticula 

 of the wall of the intestine. Like the other species of the genus it 

 secretes from its cutaneous glands a quantity of mucus, which is 

 described as having in this species the characteristic smell of 

 iodoform. 



It may be remarked that the nomenclature adopted by the author 

 is not always that which will recommend itself to the specialists of 

 the various groups which he enumerates. 



Echinodermata. 



Holothuroidea of the ' Challenger. 'f— Dr. H. Theel, who has 

 already reported on the Elasipoda or specially deep-sea forms of 

 Holothurians collected by the ' Challenger,' has issued what is really 

 a monograph of the other orders. 



About 150 species were collected, a number of which (especially 

 in the genera Cucumaria, Psolus, Stichopus, and Holothuria) are new. 

 The new genera are both aspidochirote, and are Pselopatides — a genus 

 with a " brim " round its body — and Pseudosticlwpus in which the 

 ventral ambulacral appendages are not arranged in the three longi- 

 tudinal series characteristic of Stichopus ; the anus is hidden in a dis- 

 tinct vertical furrow, and there appear to be no calcareous deposits. 



Dr. Theel is of opinion that the common ancestors of all Holo- 

 thurians were not apodous Synapta-like animals, but cucumariiform, 

 and provided with an open store-canal, ambulacral feet, and a well- 

 developed water-vascular system somewhat like that of Echinids ; the 

 Dendrochirotas appear to have varied in every possible direction, so 

 as to adapt themselves to the various modes of life consequent on the 

 infinitely varying conditions of the littoral zone. 



The present shallow water fauna has more outposts in the abyssal 

 zone than has been generally supposed, and representatives are found 

 at the greatest depth, viz. 2900 fathoms, at which Holothurids have 

 been taken, but they are not so common or so characteristic as the 

 Elasipoda. Most of the forms found below 500 fathoms are speci- 

 fically, though not generically, distinct from the shore-forms. Some 

 species have a vast bathymctrical distribution descending from the 



* Ann. Sci. Nat.— Zool., xx. (1886) Art. No. 4. 62 pp. (1 pi.). 



t Reports of the voyage of H.M.S. ' Challenger,' xiv. (1886) 290 pp., 16 pis. 



