New Forms of the Hemichordata. 153 



to procure additional specimens to check and supplement it. 

 Transverse sections were made of specimen A and longitudinal 

 sections of B. 



L— PHORONOPSIS ALBOMAOULATA. 



(Plate XVI., fig. 2.) 



PHOKONOPSIS, g. n. 



The body is asymmetrical, muscles of body being numerous and 

 more developed on left side, one nerve chord well developed, and 

 nerve ring in an involution of the epidermis, ova deposited in 

 gelatinous mass in the tube. 



In all the species of Phoronis hitherto described the body is 

 symmetrical or asymmetrical, as indicated by the development of 

 the muscles and nerve of the left side ; the muscles of the body are 

 markedly less in number than in Phoronopsis, and there is no trace 

 of any involution of the epidermis at the nerve ring ; the ova and 

 larvae are lodged in the coils of the lophophore.* 



There seems little doubt of the necessity of separating this form 

 from those hitherto described. 



Phoronopsis albomaculata, sp. n. 



Size. — The length of the animal removed from its tube was 18 mm., 

 the diameter of the body 1 mm. immediately below the lophophore 

 and 2 mm. at a distance of 4 mm. from the opposite extremity. 

 The diameter of the lophophore from tip to tip of tentacles, when the 

 animal was alive and completely expanded, was 7*5 mm. 



Tube. — The tube is larger than that of P. capensis, being 1*2 mm. 

 in diameter. It is not embedded— i.e., it does not penetrate the 

 substratum, but rather lies on it, being firmly attached by one side. 

 The substance of the tube spreads over the substratum on the 

 attached side, so that in sections it does not appear circular, but is 

 flattened on one side. 



The tube is about 30 mm. long, and, in the specimens, was irregu- 

 larly curved, so that the two ends lay near each other. Its substance 

 was apparently of the same nature as that of P. capensis, but firmer 

 and of a much tougher consistency. It was covered by grains of 

 sand and pieces of shell arranged in no definite manner. 



* Longchamps (8) observed the eggs of Phoronis Mihlleri being discharged 

 directly into the water, and suggests that this may be normal. 



