612 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
Rhynchopygus woodi.* * * § — Mr. J. W. Gregory brings forward evidence 
to show that the problematic form called by E. Forbes Echinarachnius 
woodi belongs to the genus Rhynchopygus ; this settles the question raised 
by Prof. Alex. Agassiz that it was probable that we had here to do with 
a fossil Pourtalesiid. 
Sense of Smell in Starfishes.! — M. Prouho has made a number of 
experiments with Asterias glacialis. Some of these have shown him 
that when a starfish is excited by a desire for food, the sensations which 
it obeys are perceived by the extremity of the arms ; but others show 
that it is the sense of smell and not of sight that guides it to its food. 
The “ palps ” or tentacles near the eye-like spot, which are useless for 
locomotion, were removed from a starfish, which, for a month or more 
afterwards, never showed the least excitement in the presence of either 
living or dead food ; the retention of the ocular spot makes no difference. 
It is clear, then, that the sense of smell is not diffused in Starfishes, 
but is localized in the ambulacral tubes which are unsuitable for loco- 
motion and are situated behind the eye-spot. If the ambulacral nerves 
are cut through at about 2 cm. from the extremity in such a way as 
to isolate in each a small distal portion, provided only with a small 
number of ambulacral tubes, these last become distended in the presence 
of food, but the excitement ceases at the level of the section. 
Ccelenterata. 
Actiniae of South-west Coast of Ireland-! — Prof. A. C. Haddon has 
a short notice of some species of Actinias from the deep water off the 
south-west coast of Ireland. Actinan[u]ge sp., A. richardi, Ghitonactis sp., 
C. coronaia , Sagartia sp., S. miniata , Adamsia palliata , Bolocera tuedise , 
and Actinerus sp. are recorded. 
Morphology of Skeleton of Stony Corals.§— Dr. A. Ortmann dis- 
cusses ihe morphology of the skeleton of Stony Corals in relation to the 
formation of colonies. He points out that the simplest form of a Stony 
Coral arises in the following manner : — A coral-person, at first without 
a skeleton, but with enteric cavity, pharynx, and mesenterial folds, 
becomes fixed. The parts in contact with the substratum give out a 
cuticular calcareous excretion, by which the foot-plate (basal plate of 
v. Koch) is formed. From the base of the coral radially arranged folds 
are formed between the mesenterial folds, and their ectodermal elements 
(chalicoblasts) secrete the calcareous septa. The skeleton consists, there- 
fore, of the basal plate lying on the substratum and the septa (radial 
plates of v. Koch) which rise up from it. No recent coral exhibits this 
primitive form of skeleton, but it is often found in the young buds of 
coral colonies ; the jmmitive form is always complicated by certain 
characters. The further developments of the skeleton not connected 
with the formation of colonies may be grouped thus : — (a) The septa 
become connected by epitheca ; ( b ) or by a wall ; (c) or fuse laterally to 
a varying extent. The further developments of the skeleton which are 
* Geol. Mag., vii. (1890) pp. 300-3 (1 fig.), 
f Comptes Rendus, cx. (1890) pp. 1343-6. 
j Proc. Roy. Irish Acad., i. (1890) pp. 370-4. 
§ Zeitschr. f. Wiss. Zool., 1. (1890) pp. 278-316 (1 pi.). 
