2-10 PROS'. "W. A. HASWELL : 



earlier over the anterior end of the egg than in Exogone. The stomodseal 



rudiment appears as a plug of cells which becomes extended transversely and 

 is connected with the dorsal plate by a pair of narrow cords. The plug 

 becomes invaginated by a narrow transverse slit which later becomes a deep 

 rounded pit. 



In G. kerguelensis the eggs, which are only half the size of those of 

 G. quadrioculata ('06 in long diameter), are attached dorsally, typically 

 four on each segment from the 7th to the 17th. The course of the 

 development is essentially the same as in G. quadrioculata. 



The peculiar mode of development of Grubea quadrioculata and- G. ker- 

 guelensis, flexed within the egg, appears to be shared by at least one other 

 member of the genus, viz. G. clavata. In comparing the development of 

 that species with that of G. j^usilla, De St. Joseph remarks (p. 80) : — " Chez 

 la premiere, les embryons se developpent dans l'oeuf sur le dos de la mere, 

 dont ils se separent des qu'ils sont murs en sortant de l'oeuf ; chez la 

 deuxieme ils se developpent sous le ventre de la mere et y restent fixes 

 apres qu'ils sont sortis de l'oeuf" (p. 80). 



In G. pusilloides there are few, not more than five, eggs attached loosely 

 to the ventral surface, one on each of the segments from the 11th to the 16th. 

 The mode of attachment has not been observed. The embryo is straight ; 

 the stages of development observed resemble the corresponding stages of 

 Exogone fusiifera rather than that of the other species of Grubea. 



In Sphwrosyllis liystrix the eggs are attached to the ventral surface of the 

 parent by means of the secretion of the ventral pedal glands (PL 17. fig. 30). 

 Sometimes this secretion, or that of the neighbouring integumentary glands, 

 is poured out so abundantly that it forms an investment for each ovum, and 

 this may have embedded in it numerous minute gritty particles which render 

 it very opaque ; frequently this investment is not present, and the egg 

 appears quite clear, being enclosed only in the thin vitelline membrane. 



Regarding the mode of attachment of the eggs in this form, Pierantoni 

 states (p. 24.3): " Lo strato di sostanza mucosa que involge l'uovo e sotti- 

 issimo, salvo nel punto di attacco ove e pin spesso e di consistenza quasi 

 gelatinosa, e prende l'aspetto di sottili cordoncini trasparenti che corrono 

 dair novo alia parete esterna del corpo dell' animale, intorno al punto di 

 immediato contatto." 



In addition to the delicate filaments referred to in the above quotation, 

 certain other structures become visible in the supporting plug or stalk, when 

 sections of it are stained with eosin (PI. 18. fig. 47). These are a series of 

 rod-like bodies arranged quite regularly parallel with one another and at 

 right angles to the surface of the worm. These must be formed from the 

 eosinophilous granules which, as already pointed out in the part of this paper 

 dealing with the integumentary glands, forms a part of the secretion of the 

 ventral pedal glands in this species. 



