610 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
5. Incertee Sedis, 
Philodina macrostyla and Rotifer citrinus.* — Mr. G-. Western has 
some notes on these two Rotifers, found in a bog pool on Wimbledon 
Common. B. citrinus does not seem to have been found, at any rate, in 
England since Ehrenberg’s time, and certainly differs from any described 
in the monograph of Dr. Hudson and Mr. Gosse ; the latter author was 
probably wrong in regarding B. citrinus as synonymous with B. tardus. 
Echinodermata. 
Echinodermata. | — Prof. H. Ludwig concludes his account of the 
Cuvierian organs of Holothurians, and next deals with the generative 
organs. External sexual differences are very rare, but the males of 
Thyone aurantiaca , Cucumaria laevigata , and C. elongata have a genital 
papilla, while the females of Cucumaria crocea and some other species 
have a kind of brood-pouch. 
The blood-vascular system is next described ; the vessels are 
distinguished by two anatomical peculiarities — a tendency to form 
plexuses, and the absence of an internal epithelium; in some, but 
not in all cases, calcareous corpuscles are to be found in their 
connective tissue. Radial blood-vessels may be said to be certainly 
present in the Aspido- and Dendrochirota, but it is not certain that they 
are present in the Synaptidte. The ciliated organs of the Synaptidm 
are next described ; they are found in numbers, connected with the 
mesenteries, and occasionally also on the body-wall. The coelom forms 
the subject of the fourteenth chapter ; its secondary spaces are arranged 
under the heads of pharyngeal and subpharyngeal sinus, genital sinus, 
pseudhEemal and epineural canals ; the connection of the coelom with 
other cavities of the body or with the outer world, the lining of the 
coelom and its fluid contents, form the remaining subjects dealt with in 
this part of Professor Ludwig’s work. 
Anatomical Nomenclature of Echinoderms.j: — Dr. P. Herbert 
Carpenter makes a plea for greater uniformity of nomenclature in the 
parts of Echinoderms. He suggests that the term water-tube should be 
used only to denote the madreporic or stone-caDal ; he falls foul of 
various writers who have confused the dorso-central of the Echinoid 
with the centro-dorsal of the Crinoid. As the nomenclature of the 
plates forming the dicyclic base in many Crinoids is still wanting in 
uniformity and precision, he proposed an amended nomenclature ; the 
changes will be best seen by the following table : — 
Nomenclature of ) 
J. Muller .. J 
Basals 
! 
Parabasals 
(First 
\ Radials 
Second 
Radials 
Third 
Radials 
Nomenclature of j 
Carpenter and 
de Loriol .. j 
1 
Underbasals 
Basals 
- 
Nomenclature 1 
now proposed J 
Infrabasals 
Basals 
Radials 
("First 
\ Costals 
Second 
Costals 
* Journ. Quek. Micr. Club, iv. (1890) pp. 87-91 (1 pi.). 
t Bronn’s Klassen u. Ordnungen, II. 3, Echinodermata, pp. 177-240 (pis. ix.-xii.). 
X Ann. and Mag. Nat. Hist., vi. (1890) pp. 1-23. 
