SABELLA PENICILLUS. 231 



the late distinguished Dr. W. B. Carpenter. As formerly indicated 1 this theory would not 

 stand criticism. The lining of the tube is tough and well fitted for strengthening it. 

 Orton 3 found that this species formed a tube 12*6 cm. long in less than thirty-one weeks, 

 and at this age contained well-developed, but not quite ripe ova. 



Ellis (1755) terms this form "Turkey feather," though parts of the description do 

 nob apply to the plate (33). He figures both tubes and animals in and out of the tubes. 

 He further cites it as " Fungus auricularis." 



It is probable that the Serpula periicillus of Linnseus (1758) refers to this species. 



Pallas 3 (1766) gives a fairly good figure of this form under the title of Serpula 

 peniclllus in a vessel of sea-water. Moreover, his acquaintance with the literature of the 

 subject is evident by his references to Eondeletius, Ellis and Baster. 



In this and in many other instances 0. F. Midler's (1799) figures of the animals are 

 in advance of Delle Chiaje's in minute accuracy and general pose. 



Dalyell (1853) records a series of interesting observations on the living animal in 

 confinement in regard to the branchia3, the tube-building organs, and their action with 

 mud as well as regeneration of lost parts. He expresses wonder at the faculty by which 

 the annelid communicates its purpose to one, ten or one hundred of its infinite parts whilst 

 all the rest remain inactive. He secured young specimens with few branchiae (six) and 

 watched their increase and the enlargement of the tube, as well as the attachment of the 

 end of the latter to glass or other bodies. 



Pruvot (1885) demonstrates the massive condition of the great nerve-trunks as they 

 leave the cephalic ganglia and the large size of the anterior commissures immediately 

 behind the ganglion (Plate XV, figs. 12 and 13). The great trunks have neural canals. 

 He notes and figures the chlorogogenous tissue around the ventral blood-vessel between 

 the ganglia. He figures four cephalic ganglia— two small anterior median sending twigs 

 to the tentacles (his antennae) and two large ovoid lateral ganglia. 



De St. Joseph (1894) gives an account of the variations in the number of the thoracic 

 segments and the " sillon copragogue " (ventral groove), and he concludes that the 

 differences are to be attributed only to the size of the animal or its age. He enters into 

 a detailed account of its structure. 



Cunningham 4 (1888) could find no connection between the neural canals and the 

 cephalic ganglia. The canals reached the oesophageal commissure, and he found a single 

 transverse connection between the canals in the first commissure, but no more. He 

 noticed the coagulable substance (formerly described by the author) 5 in these canals. 



Hornell (1891) describes a variety from Hillbre Island with unequal tufts of branchiae, 

 viz., sixty-one filaments on one side and thirty on the other, and as the form is a large 

 one, the branchial fan being about 4 inches in diameter, the condition is conspicuous, 

 and he imagines such may be mistaken for Spirographis. 



1 ' Ann. Nat. Hist./ January, 1872. 



2 ' Journ. M. B. A./ vol. x, p. 316, 1914. 



3 'Misc. Zool./ pi. x, fig. 1. 



4 ' Quart. Journ. Micr. Sc./ vol. xxviii, p. 271. 



5 c Proc. Roy. Soc. Edin.' 1876-77, p. 380. 



