selves. Probably it iiuw migrates directly into tishcs, ^vhich must 

 certainly often swallow these parasites in iibuiidance with Cijclopes 

 and worm-lamr. There it attains its full maturity. Prof. M()biu,s 

 thinks that it is Dlstoma ocreatum, Kud., of the herring. 



Besides the last-mentioned observer, who has published nothing 

 upon it, this animal is also mentioned, as I am told by Prof. Kupflfer, 

 by a Russian naturalist in a publication at Moscow. This, however, 

 having appeared in the Russian language, is inaccessible to me. — 

 Zeitschr. fur wiss. Zool. Bd. xxi. p. 382. 



On Halicryptus spinulosus, Von Sieh. 

 By Dr. R. von WiLLnroES-SirHM. 



As early as the beginning of April, I captured in the Bay of Kiel 

 several specimens oi Ilalicr)/p(iis si^iiuilosus, to which I assigned as 

 a dwelling-place a large porcelain pan with mud and flowing sea- 

 water. 1 soon added more to them, and quickly had some sixteen 

 Halicnjpti, which usually buried themselves at once in the mud, 

 and lay quiet during the day, but at night always wandered to a 

 greater or less distance. The specimens which I captured towards 

 the middle of the month became very tumid : dissection showed 

 strongly inflated ovaries, w^th ova ready to separate, in the females ; 

 but in the males mature spermatozoa were not yet to bo found. I 

 soon determined to make experiments in artificial impregnation, 

 and cut up females and males in the same vessel, but without causing 

 any further development of the ova, which were apparently mature. 

 I ascribed this at that time to the circimistance that the breeding- 

 season had not arrived for the males. As I oiity possessed a few 

 specimens now, I could not make use of any more for dissection ; 

 but I observed the animals all the more carefully, and remarked, 

 towards the end of April, that all the specimens which had pre- 

 \'iously been strongly inflated, now suddenly appeared thin and 

 collapsed. From this I concluded that the ejection of the sexual 

 products had probablj" taken place ; and now, as also throughout 

 the whole month of May, I examined the mud most zealously, but 

 without finding the least trace of ova. But that an ejection must 

 have taken place towards the end of April, I conclude from the find- 

 ing, in the towing-net, of a young Halicniptus, only 8 millims. in 

 length, on the 14th of Juue. It already possessed perfectly the form 

 of the older individuals, except that the sexual glands did not yet 

 show any differentiation. A small, hitherto undescribed appendi- 

 cular gland, however, could be distinctly detected in it ; and this 

 also occurs upon the middle of the genital tube in the adults. This 

 gland, which also exists in Priapidus, consists of veiy small vesicles 

 with granular contents arranged in a raceme ; and these pour their 

 secretion through a very short efferent duct into the genital tube. 



The HaUcriipii lived nearly three months in my vessels, without 

 my being able to come upon an}- trace of their earlier stages of de- 

 velopment. I could add nothing to what is already known as to 



