Dr. R. Greeff on Autolytus prolifer. 173 
I cannot understand Dr. W. 'Thomson’s habitat of the two 
species of Venus’s Flower-basket. He says, “‘ The only known 
specimen of H. speciosum is that figured by MM. Quoy & Gai- 
mard in the ‘ Yona de l’Astrolabe,’ and now in the Jardin 
des Plantes. The specimen is labelled ‘ Alcyoncellum corbicula, 
Val. Tiré par 80 brasses de profondeur dans la rade de St. 
Denis de Bourbon par M. Leschenault, 1819.’” If he will 
turn to MM. Quoy and Gaimard’s work, he will find those 
authors state that their specimen was given to them by Mr. 
Merkus, the Governor of the Moluccas. The same specimen 
cannot have two habitats or be collected by two persons at dif- 
ferent periods. Does not the label belong to the true Alcyon- 
cellum corbicula? 'The label is of little importance if Alcyon- 
cellum speciosum and A. corbicula are one species! ! 
XXV.—On Autolytus prolifer. By Dr. R. GReerr *. 
[Plate VIII. ] 
In the year 1850, Grubet established, under the name of 
Autolytus, a new genus of Annelids, previously regarded as 
forming a species of Syllis. Autolytus, indeed, has characters 
so definite and so different from those of Syllis, as is shown 
by even a cursory comparison, that this separation must be 
indicated as not only perfectly just, but actually necessary. 
For the actual establishment of this idea, however, we are 
indebted to A. Krohn, who, in his classical memoir “ On 
the Phenomena of Reproduction in Syllis prolifera and Auto- 
lytus prolifer,” first distinctly pointed out the distinctive cha- 
racters of the two generaf. The interesting processes in the 
reproduction of Syllis prolifera and Autolytus prolifer (which, 
however, as regards the latter, had certainly already been 
carefully observed by Leuckart and Frey§) are elucidated in 
this memoir from careful observation, both as regards what 
they have in common and what is peculiar in each. With re- 
gard to Autolytus prolifer, Krohn was able to confirm the 
results already in part obtained by Leuckart and Frey, al- 
though those observers still erroneously identified Autolytus 
prolifer with Syllis prolifera, and therefore also could not 
* Translated by W. S. Dallas, F.L.S., from the ‘Archiv fiir Natur- 
_ geschichte,’ 1866, pp. 352-367. 
| T rami Archiv,1850, p. 309, and ‘Familien der Anneliden,’ 1851, 
p. 62. 
ft Wiegmann’s Archiv, 1852, p. 66. 
§ ‘Beitriige zur Kenntniss wirbelloser Thiere, &c.,’ 1847, p. 91, pl. 2. 
fig. 1. For the earlier observations of O. F. Miiller, Milne-Edwards, 
Quatrefages, Johnston, &c., consult the authors just cited. 
Ann. & Mag. N. Hist. Ser. 4. Vol. i. 13 
