382 LUMBRICONEREIS IMPATIENS. 



this foot, whilst the hooks at the eightieth have a larger first fang, a shorter winged region, 

 and increased strength, This bristle would appear to belong to the lower dorsal group, 

 though the tip is now short. From the 70th to the 180th foot (Plate LXXI1I, fig. 10 a) l 

 only two black spines occur in each foot. 



The bristles on the whole approach those of Zygolobus, though differing in arrangement, 

 and especially anteriorly. 



Fage 2 notes that the segmental organ of this form is green, and that the genital 

 funnel is of large dimensions. 



A small form dredged in considerable numbers off S.W. Ireland at log 55 in 

 twenty-three to thirty-eight fathoms in 1886 shows certain features resembling the fore- 

 going. At the fifteenth foot some of the winged hooks have very slender tips, the points 

 (hooks) being very minute, but the spines are pale. 



Reproduction. — An example procured in Shetland by Dr. Gwyn Jeffreys in July had 

 well-developed ova. 



This species attains a comparatively large size in the south. Thus De St. Joseph 

 records one of 34 cm. from St. Vaast (P. Fauvel), and those from Plymouth cannot be 

 much short of two feet. 



In Delle Chiaje's ' Memorie ' (1825) the maxillas are represented with only four teeth, 

 as observed in the British examples. Two of the figures are omitted in the ' Descrizione.' 

 He calls the species " Tremolino," and besides the dental apparatus, he describes and 

 figures the alimentary canal, circulation, and nervous system. 



This form differs from Lumbriconereis tingens, Keferstein, in having the long narrow 

 hooks anteriorly unjointed. It appears to correspond with Lumbriconereis impatiens of 

 Claparede from the Mediterranean, a form long previously mentioned by Delle Chiaje as 

 Lumbricus fragilis (non 0. F. Midler), as above noted. 



Claparede (1868) cleared up certain ambiguities in Grube's description, especially in 

 the structure of the hooks anteriorly and posteriorly. 



Ehlers (1868) observes that his L. breviceps has bristles similar to those of L. 

 impatiens. 



Cams, again (1885), thought this form synonymous with Grube's Zygolobus lauren- 

 tianus, which it can scarcely be. 



Pruvot (1885) represents two somewhat clavate lobes of the inferior region of the 

 cerebral mass which pass to the ciliated sacs at the posterior part of the head. He 

 regards the lateral elevations at the mouth as the homologues of the palpi. 



Miss Florence Buchanan 3 (1893) describes spirals of different lengths occurring in 

 this species from Naples. She likewise mentions that in this annelid and in Halla 

 regeneration of head and tail occurs. 



Lo Bianco 4 found this species mature at Naples from May to September. 



1 The artist has omitted the long hooks in this figure. 



2 ' Ann. Sc. Nat./ 9 e ser., Ill, p. 380, fig. 36, 1906. 

 8 ' Quart. Journ. Micr. Sci./ n.s., vol. 34, p. 537. 



* f Mitth. Zool. Stat. Neap./ xiii, p. 487, 1899. 



