944 General Notes. [September, 
the rupture of the perisarc, and has, when set free, eight tentacles, 
a thin globular bell, and a simple proboscis. In examples two weeks 
old, the stomach is suspended some distance below the sub-umbrel- 
la by a transparent mass of large cells, and the lower surface of the 
wide velum is pushed out to form eight hemispherical pouches, 
four perradial and four interradial. C. octonaria, as stated by 
McCrady, lives in its young state as a parasite within the bell of 
Turritopsis. The medusa of N. dachei L. Ag., is derived from a 
fixed hydroid closely related to Bougainvillea and Eudendrium. 
In the simplest stage of the medusa there are four tentacles, but 
others bud from the same points, forming clusters. In P. gi 
the medusz escape, one at at a time, from a gonotheca containing 
three or four. The apical process in Amphinema is not present 
in the larval medusa, but commences to develop on the third day, 
Worms. — A recently issued part of Semper’s “Reisen im 
Archipel der Philippinin” contains an account of the Sipunculids 
by Drs. De Man, Bulow and Selenka. Seven colored plates ac- 
company the text. A magnificent atlas of the Rhabdoccelida, 
containing twenty highly finished and colored folio plates, has 
been issued by Dr. L. von Graff, to accompany his extensive 
monograph of the Turbellaria, the first part of which contains 
descriptions of 259 species of Rhabdoccelida. The otocysts 
of Arenicola grubii, according to M. Et. Jourdain, are situated on 
the dorsal aspect in the midst of muscular fibers, and are fixed 
by their conjunctive envelope, which is prolonged over them and 
surrounds them, They are not in immediate contact with the 
cesophagean commissures, but are simply united to them by sev- 
eral nerves. : 
Mollusks—Sowerby’s “Thesaurus conchyliorum” has reached 
its forty-second part. The last issue contains monographs of 
Teredo and Kupheo, Gastrochzena, Fistulana, Saxicava, the Ptero- 
poda, and numerous other genera, including Tridacna and 
popus, the varieties of which are very fully figured. 5j 
Drouet (Bailliere, Paris), has put forth a monograph of the bor 
ionidæ of Italy, which comprise forty-three forms of Unio, SIX ° 
Microcondylus, and thirty-one of Anodonta. The basin of zri 
Po and Upper Italy is one of the richest districts in Europe biota 
respect to this family. 
Arachnids.—At a recent meeting of the Academie Royale des 
Sciences of Belgium, M. MacLeod gave a preliminary commu- — 
nication upon the anatomy of Trombidium, Argas, Hydrachna 
and Gamasus. The suckers of the two first genera differ fee 
Hip- 
Henri 
canals of the salivary glands has been followed. Certain granul 
contained in the terminal intestine of Argas are formed in 
