ZOOLOGY AND BOTANY, MICBOSOOPY, ETC. 63 



It was the anterior part of the body that was lodged in the tower. 

 After the rainy period at the end of September all the tubular interior 

 of each tower (forming a continuation of the subterranean gallery) 

 was quite free ; but a few days later it was obstructed by recent de- 

 jections. M. Trouessart supposes that the calotte or cap of the tower, 

 getting hard in air, a time comes when the worm can no longer burst 

 the upper wall as before, to place its dejections outside (so increasing 

 the height of the tower), but deposits them within. Thus a long 

 period of rain is necessary for these towers to rise regularly. The 

 towers probably serve to protect the galleries from rain, and to afford 

 a breathing place for the worms, where they are not seen by birds. 



Hamingia arctica.* — This remarkable Gephyrean was first de- 

 scribed by Keren and Danielssen f from a spirit specimen, and 

 subsequently by Dr. Horst J from two sent to him. Prof. E. Eay 

 Lankester having obtained a fresh specimen as well as one in spirit, 

 is able to add to our knowledge of its character. He finds it is 

 really intermediate in its combination of characters between Bonellia 

 and Thalassema. Owing to their not having known the frontal hood 

 or proboscis, Koren and Danielssen somewhat over-estimated the 

 closeness of its relationship to Bonellia. On the whole it may be 

 said that Hamingia has in internal organs a closer resemblance to 

 Bonellia, but in external shape and characters a closer resemblance to 

 Thalassema. The feature in which it is quite peculiar is the absence 

 of genital setae in the female and the correlated existence of one or of 

 two prominent papillae which carry the genital pore or pores. 



The new facts recorded, additional to the observations of Koren 

 and Danielssen and Horst, are briefly as follows ; — 



1. Hamingia arctica occurs on the Norwegian coast in latitude 60°, 

 and at the comparatively small depth of 40 fathoms. 



2. It has a frontal hood or proboscis resembling that of Thalassema 

 which is easily broken off, as in Thalassema and Echiurus. 



3. The corpuscles of the perivisceral fluid are coloured by 

 haemoglobin. 



4. The male (five of which, l-12th in. long, were found within the 

 dilated pharynx of the female) is a diminutive parasite living upon 

 the female, as in the case of Bonellia ; it is provided with a pair of 

 large genital setae, although such setae are absent in the female. 



5. Though usually there are two, yet there may be only one 

 uterus, and one genital pore, as in Bonellia. 



Anatomy of Prorliynclius.§— J. v. Keunel discovered specimens of 

 Prorhynchus in the neighbourhood of Wiirzburg, and has also examined 

 examples from other localities. Unlike M. Schultze, who regarded it 

 as a Nemertine, v. Keunel looks on this genus as belonging to the 

 Ehabdoccela ; the first point in favour of this view is the character of 

 the digestive tract ; the mouth lies at the most anterior end of the 



* Ann. and Mag. Nat. Hist., xi. (1883) pp, 37-43 (2 fio-s.). 



t Cf. this Journal, i. (1881) pp. 45, 890. 



i Ibid., p. 891, and ii. (1882) p. 50. 



§ Arbeit. Zool.-Zoot. Inst. Wurzburg, vi. (1882) pp. 69-90 (1 pi.). 



