GEPHYREA. 
Verm. 37 
in the mesenchym under the latter. It acquires a lumen, and then forms 
a tube from which numerous evaginations arise to form the testicular 
■sacs, while the original tube becomes the vas deferens. The copulatory 
Drgan arises by invagination from epidermis. 
GEPHYREA. 
New Species. 
. Bonellia pumicea, Malay Archipelago, Sluiter, p. Ill, n. sp. 
Phascolosoma macer, Malay Archipelago, id. p. 114, n. sp. 
Phymosoma rhizophora , Malay Archipelago, id. p. 119; P.demanni , 
Malay Archipelago, id. p. 121 : n. spp. 
Phoronis psammophila, Faro, Messina, Cori, n. sp. 
New Descriptions, Biology, Distribution. 
Collin (4) : Echiurus chilensis, Max Muller. 
Cori : Biology and Distribution of Phoronis. 
Garstang. 
Shipley (2) : Phymosoma weldonii. 
Sluiter says that most species of Phymosoma form canals in calcareous 
rocks, probably boring them by means of the secretion of the numerous 
integumentary glands. They make their own canals, and do not creep 
into other holes and crevices ; and they remain all their life in the same 
hole. P. rhizophora is a mud-dweller. Almost all the A spidosiphotiidce, 
Dendrostomidce , and Clceosiphonidce , are true stone-dwellers. Aspidosiphon 
gigas is a mud-dweller. Author found five males in oesophagus of Bon- 
nellia pumicea. 
Histology. 
Cori (see below). Cu^not, pp. 593-613. 
Jourdan. Ward (see below). 
Morphology. 
Cori commences with a biological description of Phoronis psammo- 
phila , n. sp., from Faro, Messina. A hitherto undescribed layer enters 
into the composition of the wall of the tentacles. Here the epidermis is 
provided with a cuticle ; but, contrary to what occurs in the rest of the 
body-wall, there is no basal membrane, but in its place there occurs a 
layer of supporting tissue (Stiitzsubstanz). Between this layer and 
epidermis are very delicate muscle-fibres. On the inner surface is the 
peritoneal lining of tentacle-cavity. Author regards the “ Stiitz- 
substanz ” as a product of the somatic peritoneum. The epistom 
contains a entity which passes on each side into cavity of lophophore. 
Muscle-fibres, present elsewhere on wall of intestine, are absent from 
1891. [ VOL. .XXVIII.] F 9 
