ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
451 
dorsal cirri, the alimentary canal, the circulatory system, the nephridia, 
and the generative elements are respectively passed in review, but details 
only are given. 
Young Stages of Magelona.* — The same author takes the oppor- 
tunity of the discovery of several stages of the young of this worm to 
add to our knowledge of some details. Claparede’s unknown larval Sjpio 
appears to be the larva of a species not unknown at St. Andrews. 
Auditory Organs of Alciopidae. f — M. E. Beraneck notes that 
although Greef was wrong in interpreting glandular structures near the 
eyes of Alciopidae as auditory sacs, otocysts are indeed present. They 
are two little sacs attached in the larva to the first segment of the trunk ; 
they arise as ectodermic buds, include external epidermis, internal 
sensory cells, unicellular glands and organic (granular) otoliths of 
nuclear origin, and are innervated by the sub-oesophageal ganglion. In 
Asterope there are four sacs, the second pair innervated from the second 
ventral ganglion, and on the other segments of the body the parapodial 
cirri are sensory. In fact, the otocysts of these Annelids are transformed 
cirri. The type found in Arenicola and other forms, and in the Trocho- 
phore larva, is of course quite different and doubtless more primitive. 
Beraneck is not inclined to accept the view of Eisig and others that 
the lateral sense-organs of Vertebrates are homologous with those of 
Annelids. He believes that the auditory organs of bilateral Metazoa 
arise independently in each phylum. In Molluscs and Crustaceans, the 
otocysts combine the two functions of hearing and orientation ; those of 
Vertebrates are ( pace several authorities) for hearing only. It may be 
said that the two functions are dependent on one — that of receiving 
vibrations from the surrounding medium ; but the sense of orientation 
is a complex physiological resultant in which various sensory organs 
besides otocysts may concur. 
13. Nemathelmintlies, 
Hew Genera of Nematodes. :f — Mr. N. A. Cobb describes ten new 
genera and twenty new species of Nematodes ; they were all free-living 
and marine, and came from the Atlantic, Indian, and South Pacific 
Oceans. Tricoma (T. cincta) has the cuticle so coarsely striated as to 
suggest the segmentation of an Annelid. Pelagonema (P. simplex , from 
Ceylon) is related to Oncholaimus, but there are no teeth on the walls of 
the pharynx. JDemonema (D. rapax, from Naples) is allied to Enoplus , 
but wants the distinct teeth characteristic of that genus. For Platycoma 
(P. cephalata, from Naples) the generic are not distinguished from the 
specific characters. Bathylaimus {B. australis , from Port Jackson) is 
apparently related to Oncholaimus, but, like Pelagonema , has not its 
teeth. Synonchus (S. fasciculatus and S. hirsutus , from Naples) is also 
related to Oncholaimus ; the dorsal gland has the peculiarity of emptying 
into the lumen of the oesophagus at some distance from the mouth, a 
fact which supports the opinion that these organs are salivary glands. 
* Quart. Journ. Micr. Sci., xxxvi. (1894) pp. 66-74 (1 pi.). 
f Rev. Suisse Zool., i. (1893) pp. 463-500 (1 pL). 
X Proc. Linn. Soc. N.S.W., viii. (1894) pp. 389-421 (50 figs.). 
