646 
ZOOLOGICAL LITERATURE. 
parasitism. Many of these disks enclose one or two clear 
vesicles ; but no reagent demonstrates the existence of a 
nucleus. 
The corpuscles of the second class bear to the former a certain 
resemblance, but are vastly larger, with longer processes ; their 
contents are often rendered areolar by the presence of a large 
number of vesicles ; but the most remarkable characterfstic is 
the presence of a hard body in their interior. This hard body, 
varying in colour from a clear brown to a deep black, is like a 
sort of cylindrical rectilinear or curved rod, sometimes sinuous, 
the two extremities of which are sometimes twisted into a wisp, 
sometimes flattened out. These extremities are always covered 
with a thin layer of the protoplasmic prolongations ; they are 
insoluble in strong or weak acetic acid. Gab. Costa appears to 
have been the first to point out these strange organisms. Kowa- 
lewsky briefly mentions them in his Memoir on Ctenophora 
(vide Zool. Eec. 1866, pp. 621 and 632). 
Ophelia polycheles, sp. n., Grube, 1 . c. p. 635, Taf. 7. fig. 5. 
' Polyophthalmus pallidus, sp. n., Olaparede, 1. c. p. 294, pi. 31. fig. 7. 
Arenicolea. 
Arenicola yruhiij sp. n., Clapar5de^ /. c. p. 290, pi. 19. fig. 2. 
Ariciea. 
Aricia foetida^ sp. n., Olaparede, 1. c. p. 306, pi. 20. fig. 2. 
Theodisca liriostoma^ sp. n., Olaparede, 1 . c. p. 310, pi. 24. fig. 2. 
Leucodorea. 
Polydora ayassizii, sp. n., Olaparede, 1 . c. p. 314, pi. 22. fig. 1 j 2 \ hoplura, 
sp. n., Olaparede, /. c. p. 318, pi. 22. fig. 2 3 P. attenuata^ sp. n., Olapari^de, 1. c. 
p. 320, pi. 21. fig. 3. 
Spio fidiymosits, sp. 11 ., Olaparede, 1 . c. p. 322, pi. 23. fig. 1 5 S. mecznikotoi- 
anus, sp. n., Olaparede, 1 . c. p. 324, pi. 23. fig. 2. 
Nerine sarsiana, sp. n., Olaparede, 4. c. p. 330, pi. 21 . fig. 4 j N. auriseta, 
sp. n., OlaparMe, /. c. p. 331, pi. 24. fig. 2. 
Prionospio malmgreni, sp. n., Olaparede, I, c. p. 333, pi. 22. fig. 3. (The 
diagnosis of the genus Prionospio is emended by Olaparede.) 
Polydora {Leucodore, Johnst.) calcarea, Temp., is described by Lankester 
(1. c.) as boring into rocks composed in whole or in part of carbonate of lime. 
He believes this boring to be effected by means of an acid, and mentions that 
specimens of this species placed on litmus-paper gave a strong acid reaction. 
In the ^Annals’ for July, p. 76, Lankester refers to papers on Lithodomous 
Annelids, by Grube and L.-Duthiers. 
' Leucodore (Polydora) dliata^ J ohnst., is figured, and the tentacles, bristles, 
4 nd anal segments are carefully described by MTntosh, /. c. p. 283, pis. 17 and 
19. In his remarks on the boring of this Annelid, ho disproves the theory 
pf the boring-powers of the Annelids being due to a purely chemical agency j 
