212 IBLA QUADRIVALVJS, 



would they all have remained, and so formed a polyandrous 

 establishment, such as we shall presently see occurs some- 

 times in Scalpellum? This must remain quite uncertain. 



In this same hermaphrodite specimen of I. quadri- 

 valvis, the two ovigerous lamellae contained some hundreds 

 of larvae in the first stage of development, which were 

 liberated from their enveloping membranes by a touch of 

 a needle : they were about the y^ths of an inch in length, 

 and presented all the usual characters of larvae at this 

 period. What a truly wonderful assemblage of beings 

 of the same species, but how marvellously unlike in 

 appearance, did this individual hermaphrodite present ! 

 We have the numerous, almost globular larvae, with 

 lateral horns to their carapaces, with their three pair of 

 legs, single eye, probosciformed mouth and long tail : — 

 we have the somewhat larger larvae in the last stage of 

 development, much compressed, boat-formed, with their 

 two great compound eyes, curious prehensile antennae, 

 closed rudimentary mouth and six natatory legs so diffe- 

 rent from those in the first stage : — we have the two 

 attached males, with their bodies reduced almost to a 

 mouth placed on the summit of a peduncle, with a minute, 

 apparently single eye shining through the integuments, 

 without any carapace or capitulum, and with the thorax 

 as well as the legs or cirri rudimentary and functionless : 

 — lastly, we have the hermaphrodite, with all its com- 

 plicated organisation, its thorax supporting six pairs of 

 multi-articulated two-armed cirri, and its well-developed 

 capitulum furnished with horny valves, surrounding this 

 wonderful assemblage of beings. Unquestionably, without 

 a rigid examination, these four forms would have been 

 ranked in different families, if not orders, of the articu- 

 lated kingdom. 



Concluding Remarks. — If the creature which I have con- 

 sidered as the male of Ibla Cuniingii be really so, and the 

 evidence formerly given seems to me amply conclusive, 

 then the animal just described, from its close affinity in 

 every point of structure with the former, assuredly is the 



