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coast in galleries excavated in the red sandstone (not limestone) which 

 is exposed by the springtides. The galleries appear to be those formed 

 by the Lamellibranch Gastrochaena^ which the Thalassema appro- 

 priates. It is not difficult to collect from fifty to a hundred specimens 

 of the worm in the course of an hour, so abundant are they. 



The more interesting results which I obtained from the study of 

 these specimens are as follows. 



Colour. The general coloration is correctly described by Forbes. 

 The proboscis is of a fine golden yellow colour which gives place to an 

 orange yellow tint about the anterior region of the body. The middle 

 region of the body is pink (due to the presence of Haemoglobin in the 

 muscular tissue of this region of the body-wall) whilst the hinder part 

 of the body is white. 



Perivisceral or coelomic liquid and haemoglobinous 

 corpuscles. When the body- wall of a liviug specimen is cut through 

 a liquid issues from the body-cavity of a very remarkable character. It 

 is opaque and of a very dark red or madder-brown colour. Professor 

 Greeff who has examined Echiurus Pallasii and his new species 

 Thalassema Baronii in the living state, gives no description of any 

 such intense colouring of the perivisceral fluid in those species, and I 

 conclude from his statements as to the appearance of the perivisceral 

 corpuscles that the liquid in those species appears colourless. 



As is well known the perivisceral liquid of another Gephyraean, 

 viz. Sipunculus nudus^ is of a delicate rose colour and opaque on account 

 of its abundant corpuscles. The pink colouring matter of Sipunculus 

 nudus impregnates the substance of special corpuscles which seem to 

 exist for the express purpose of carrying this colouring matter. The 

 same coloured body also impregnates a bjind of tissue running along 

 the intestine and also the inner sheath of the nerve-cord. 



I examined this pigment in 1871 at Naples and found it to be 

 soluble in water but not giving any absorption-spectrum. Kruken- 

 berg (Vergleich. -physiol. Studien, 3. part p. 86) has recently proposed 

 to call it Haemerythrin and assumes that it has (as I had already sug- 

 gested) properties similar to those of Haemoglobin. Dr. Kruken- 

 berg goes further than this. I had carefully proved by examination 

 with the spectroscope and super-position of spectra, that the red colour 

 of the corpuscles of Phoronis was due to Haemoglobin and similarly 

 that the colour of the perivisceral corpuscles of the Chaetopods Capi- 

 tella and Glycera was due to Haemoglobin (Proceedings of the Royal 

 Society, 1873). Krukenberg without having examined anyone of 

 these animals, states that probably Haemerythrin and not Haemoglobin 

 is the cause of the red colour of the corpuscles of the first-named [Pho- 



