THE NAUTILUS. 123 



P. (Syrnola f) winhhyi, is described from Branford, Conn. Turbo- 

 nilla is divided into five subgenera — Ptycheulimella, Chemnitzia, 

 Turbonilla, Strioturbonilla and Fjrgiscus. A new subspecies, T. 

 (^Strioturbonilla) busfiiana abyssicola, is described from 1290-1537 

 t'atlioms off Martlia's Vineyard. 2\ verrilli, vinecz, hranfordensis, 

 huteonis, winkleyi, senilis, sumneri, cascoensis, whiteavesi and edward- 

 ensis of the subgenus Pyrgiscus are described as new; the last two are 

 from Prince Edward Island. T. mighehi is proposed for T. costti- 

 lata Verr. 1873 {non Ris^so 1826). Under Odostoniia six subgenera 

 are recognized — Cbrysallida, Evalina, lolaea, Menestho, Odostomia 

 and Liostomia. The following are new : 0. {Chrysallida) bushiana 

 and willisi, 0. (Evalina) winkleyi, 0. {lolaea) hendersoni, 0. (^Men- 

 estho) trijida bedeqiunsis and bisutiiralis ovilensis. 0. morseana is 

 proposed in place of 0. sulcata Verr. 1880 {non A. Adams 1860). 

 The Pyramis striatula Couthouy forms the type of a new genus, 

 Couthouyella. There are excellent figures of nearly all the species 



C. W. J. 



Natural History, Organization and Late Development 

 OF the Terediniu^ or 8hip-vvorms. By Charles P. Sigerfoos. 

 (Bulletin of the Bureau of Fisheries, xxvii, pp. 193-231, pi. vii- 

 xxi.) Xylolrya gouldi, Teredo dilatata and 7. navalis from Beaufort, 

 N. C., have been investigated. T. navalis carries the eggs in the 

 gills, but in the other species they are laid free into and fertilized in 

 the water. In one case 7'. dilatata was estimated to produce one 

 hundred million eggs. The egg develof)S into a typical small bivalve 

 having a swimming organ (velum). Throughout the summer these 

 may be found crawling over wooden structures in search of iavorable 

 crevices for attachment. Once attached by a single long byssus 

 tliread, the larva loses the velum, scrapes away the surface of the 

 wood with the ventral edges ot the shell- valves, and the foot develops 

 into a pestle-shaped organ which assists the shell in burrowing. ()n 

 the external surface ot the valves at the anterior edges is formed the 

 first row of small teeth, which at this and later stages are the 

 mechanical agents by which the animal bores into the wood. This 

 transformation has taken place within two days from the time the 

 larva has settled, and afterwards the animal rapidly becomes an 

 elongate ship-worm. Evidence is given showing that the ship-worm 

 may reach a length of 4 feet and diameter of 1 inch in about one 

 year. The sexes are separate in adult ship-worms, but young indi- 

 viduals of X. gouldi are frequently hermaphroditic, in which case the 

 male cells develop first. The anatomy is very fully described and 

 illustrated. This timely paper, a valuat)le addition to our knowl- 

 edge of Pelecypod morphology, can be obtained of the Bureau of 

 Fisheries. H. A. P. 



