222 



Mr. R. I. Pocock on a new Genus 



EXPLANATION OF PLATE XIII. 



bf, internal chamber. 



I)}; glands. 



e. m, entodermal muscles. 



em. z, embryonal cells. 



Ltn, longitudinal muscles. 



Mff, stonaacli. 



Mk, buccal cone. 



ikf.o, 'mouth-opening. 



M' o', inner mouth-opening. 



Mw, gastral pads. 



JV, nematocysts. 



Nv, nervous layer. 



Fiff. 



pz, parasitic cells. 

 Qm, transverse muscles. 

 s, developed septa. 

 5', young septa. 

 sf, fibrils of the sense-cells. 

 st. I, supporting lamella. 

 st. z, supporting cells. 

 st'. s', cells of the supporting la- 

 mella, 

 sz, sense-cells. 

 t. F, transverse bands. 

 z.f, intermediate chamber. 



surface 



1, Folypariutn amhulans enlarged 2| times ; the upper 

 covered with buccal cones, the lovrer with acetabula: 



Fig. 2. A longitudinal section of Polyparium, showing buccal cones above 

 and acetabula below ; small and large septa. Transverse bands 

 {t. F) strongly developed. 



Ftff. 3. A septal stoma. 



Fiff. 4. Section of the wall of a buccal cone, in which all the layers 

 characteristic of an Actinia (muscles, nerves, fibrillar nemato- 

 cyst layer, &c.) occur. 

 Section of the buccal disk which stretches between the buc- 

 cal cones. The layers follow the same order as in the last 

 figure. 

 Section of the pedal disk near an acetabulum. 

 Teased-out preparation from the buccal disk, in which are to b6 

 distinguished nematocysts, sense-cells, nerve- and muscular 

 layers. To be noted the relations which exist between the 

 muscles (m) and the fibrillae emanating from the nematocysts. 



Fig. 8. Teased-out preparation from the pedal disk, in which gland- and 

 sense-cells are to be distinguished. 



Fig. 9. Entoderm filled with parasitic ceUs. 



Fig. 5. 



Fig. 

 Fig. 



XXII. — Description of a new Genus and Species of Poly- 

 zoniclge. . By R. Innes Pocock. 



[Plate XIV.] 



PsEUDODESMUS, genus novum. 



Platydesmo (Lucas) propinquum. Corpore longo, supra tuber- 

 culorum, infra carinarum serie quoque latere praedito. Seg- 

 mentorum numero majore quam septuaginta ; segmento ultimo 

 postlce baud acute ; segmentis, primo et ultimo exceptis, carinas 

 prope ad libellam emergentes parte lateris inferiore geren- 

 tibus et dorsum medium canaliculatis. Carina quaque, tribus 

 anticis exceptis, in margins laterali foramen repugnatorium 



