436 SUMMARY OF CURRENT RESEARCHES RELATING TO 
of the mesogloea at the bases of the tentacles. The author proposes to 
place PJiellia pectinata and P. spinifera , which were described by 
Hertwig, in a new genus which he calls Chitonanthus. Our space will 
not permit of our enumerating the large series of new species which 
were found in this collection. In conclusion, the author briefly dis- 
cusses the geographical and bathymetrical distribution of the Actiniaria, 
but it is hardly yet time to enter into an exhaustive discussion on this 
subject. The researches of the ‘ Albatross ’ have, however, demonstrated 
that certain deep-sea species have a very wide distribution. 
Zoanthus chierchiae sp. n.* — Prof. A. R. v. Heider describes this 
new species from the 4 Yettor Pisani ’ collection. The colony occurred 
on loose stones ; the polypes are close together, connected by coenen- 
chyma; the individuals measured at most 12 mm. in length, with an 
oral disc 4-5 mm. in diameter : the largest had 40-55 tentacles in a 
double ring. The species seems nearest to Z. mcicgillivrayi of Haddon 
and Shackleton. Like some other investigators, Yon Heider notes 
that numerous variations from the norm occur in the mesenteries of 
Zoantheee. A full description of the minute structure is given, but we 
can only refer to a few points. Between and beside the canals in the 
body-wall there are certain ceils and fibres imbedded in the mesogloea, 
which are usually regarded as connective or muscular ; these von Heider 
believes to be nervous. The mesenteries, originally muscular and 
respiratory, have here undergone further differentiation, for many of 
them possess a glandular cushion, probably digestive. No reproductive 
cells were observed, but the author believes that a marked proliferation 
of endoderm in the deeper parts of the mesenteries must be regarded as 
serving for the reception of the genital elements. 
New Rhizostoma.'f — Mr. K. Kishinouye describes under the name 
of Mastigias pliysophora a new Rhizostome which is found abundantly in 
summer on the coasts of Shima and Sagami. The largest specimen is 
about 100 mm. broad, but specimens as much as three times as wide are 
said by fishermen to have been seen by them. The author confines 
himself to a comparatively short general account of this new species. 
Character and Distribution of Perigonimus.J — Prof. C. W. Hargitt 
(along with Dr. H. L. Osborn) found a species of this interesting genus 
of Gymnoblastic Hydroids in the waters of Long Island, and has 
followed up the quest at Naples. 
Hargitt slightly modifies the generic characters given by Hincks : — 
Coenosarc sheathed in a chitinous, sub-chitinous, or gelatinous perisarc ; 
hydrocaulis branching or simple, from a filiform hydrorhiza ; hydranths 
fusiform, with a single verticil of filiform tentacles surrounding the 
base of a conical hypostome ; gonophores developed from the coenosarc. 
Gonozooids free and medusiform. Umbrella deep bell-shaped ; manu- 
brium short; radiating canals four; marginal tentacles two or four, 
often increasing with age, springing from non-ocellated bases. 
The genus is amongst the simplest of Gymnoblastic hydroids; at 
least twelve species are known ; the habit is distinctly commensal — on 
* Zeitschr. f. wiss. Zool., lix. (1895) pp. 1-28 (3 pis.). 
t Zool. Mag., vii. (1895) pp. 86-8 (1 pi.). 
X MT. Zool. Stat. Neapel, xi. (1895) pp. 479-87. 
