40 Prof. E. Kay Lankester on Hamingia arctica, 



to add to the description of Koren and Danielssen besides the 

 existence of a Thalassema-Mke proboscis, owing to my speci- 

 men being in the fresh state. This was the existence in 

 the liquid of the body-cavity of corpuscles impregnated with 

 haemoglobin. These corpuscles were so abundant as to give 

 the perivisceral fluid a bright blood-red colour. I had previ- 

 ously (Zool. Anzeiger, 1881, no. 87) published a similar 

 observation with regard to Thalassema neptuni. In Bonellia 

 I can state, from my own observations made at Naples in 

 1874, that the perivisceral fluid is colourless. It also appears 

 to be colourless in Echiurus. 



Mr. Norman's Specimen. — The second specimen of Hamin- 

 gia from Lervik, namely that dredged by Mr. Norman two 

 years ago, came into my hands well preserved in spirit. It 

 was a little larger than that dredged this summer. It had 

 suffered in regard to the proboscis, as is so usual in preserved 

 specimens of the Echiuridse*. A very short remnant of the 

 base of the proboscis only was preserved, thus agreeing with 

 the specimens studied by Koren and Danielssen and by Dr. 

 Horst. 



Single Uterine Pouch. — The most remarkable fact about 

 this second specimen was that only one genital papilla and one 

 genital orifice was present instead of two, as in all the other 

 specimens of Hamingia described. Corresponding to this single 

 orifice was a single uterine pouch. This abnormality brings 

 us to a condition which is normal in Bonellia, where only one 

 uterine pouch is found. At the same time it is worth noting 

 that the very delicate hyaline walls of the uterine pouch of 

 Hamingia (though muscular) differ from the thick dense walls 

 of that of Bonellia j as also does the internal orifice or funnel. 

 Abnormalities in the number of uterine or spermatic pouches 

 are not uncommonly to be observed in Thalassema neptuni. 



The Male of Hamingia. — In this second specimen of Ha- 

 mingia (Mr. Norman's) I was fortunate enough to discover 

 the male sex. As in Bonellia, so in Hamingia the male is a 

 minute worm-like creature which lives as a parasite upon and 

 in the female. I found five of these minute males (each -^ 

 inch long) within the dilated pharynx of the female Hamingia. 

 I did not find any males in the uterine pouch, which was 

 distended by fully formed eggs and was nearly as long as the 

 whole body. 



I may mention in illustration of this fact, and as explaining the mis- 

 take made by Koren and Danielssen, that in a collection of twenty well- 

 preserved specimens of Echiarns unicinctus from Japan, brought home 

 by the ' Challenger/ not one had the proboscis in place j all showed a 

 crescentie ridge whence the proboscis had been broken away, as in Koren 

 and Danielssen's Haminaia. 



