47 102 Proceedings of the Royal Irish Academy. 



numerous branches on the gills. Of the other two species, P. Steenstrupi has 

 been examined by Malmgren, Langerhaus, and Mesnil, with different results. 

 According to Malmgren, the species has no eyes, there are two rows of 

 branches on the gills, crochets are absent from the dorsal divisions of the 

 posterior feet, and those in the ventral divisions have only a single spine on 

 the crown. According to Laugerhans, who found his specimens at Madeira, 

 the head bears two pairs of eyes, there are four rows of branches on the gills, 

 crochets are present in the dorsal divisions of the posterior feet, and they 

 have five spines above the main tooth. Mesnil re-examined the specimens 

 described by Malmgren and Langerhaus, and confirmed the identity of the 

 two species. He pointed out that the spines on the crown of the crochets 

 are arranged in pairs. 



A large number of Irish specimens of this species have been collected, and 

 they all show the same characters with very little variation. In only a single 

 specimen are the eyes absent (Southern, 1910, p. 236), and this was a small 

 immature worm. On the whole, they agree with the description of P. 

 Steenstrupi given by Laugerhans and Mesnil. 



The third European species, P. Malmgreni, has been described by Claparede 

 (1S69, p. 73), and by Marion and Bobretzky (1875, p. 84). It appears to 

 differ from P. Steenstrupi in baring no crochets hi the dorsal divisions of the 

 posterior feet, and in having only two spines above the main tooth of the 

 crochets. The head as figured by Marion and Bobretzky (1875, pi. xi, fig. 20) 

 agrees exactly with Irish specimens of P. Steenstrupi. The statement that 

 dorsal crochets are absent, and that those in the ventral divisions have only 

 two spines, may be based on faulty observation. The anal segment and the 

 structure of the gills agree closely with the Irish specimens ; and it appears 

 to me piobable that a further examination of the Mediterranean forms will 

 show that the two species are identical. Mcintosh (1914, p. 82), who has 

 examined some of the Irish specimens, refers them to P. Malmgreni. In his 

 remarks, however, he ignores the chief character separating the two species, 

 viz., the presence or absence of crochets in the dorsal divisions of the posterior 

 feet. 



Habitat. — Llacksuh Bay — Dredged on two occasions, in 2-3 fms. Clew 

 Bay — Dredged in 18 fms. 



Dislribulion. — Norway; Iceland ; Greenland ; Madeira. 



Spiophanes bombyx (Claparede). 



L896. Sjtiophfiiics bomby,v. Mesnil. p. 249. 



This species is rare in the district. Two specimens weir obtained by 

 _ing in sand near low-water mark in Blacksod Bay. and several were 

 • hedged in Clew Bay. 



