the South Coast of New England. 145 



Haan (a genus before known only from the North Pacific), and 

 a species of il/M/ii'(^a. These were associated with Etipagurus 

 hernhardus, E. Kroyeri^ and the remarkable Parapagurus 

 pilosimanuSj which were before known from the north. But 

 the most interesting Anomura were two species of a new 

 genus [Hemipagurus] , allied to the little-known genus Sjnro- 

 pagurus, Stimpson, but differing conspicuously in the form 

 and position of the single sexual appendage of the last thoracic 

 somite of the male, which arises from the coxa of the right 

 side, while in Spiropagurus it arises from the left side. Both 

 the species of Hemipagurus inhabit cases formed by a colony 

 of Epizoanthus or by an individual of a species of Adamsia. 



The unsymmetrical development of the external sexual 

 organs of the males of this genus is accompanied by a most 

 remarkable difference in the corresponding internal organs. 

 The abdominal viscera are not sufficiently well preserved in 

 the ordinary alcoholic specimens for a full anatomical and 

 histological investigation ; but the following observations, 

 though incomplete, are so novel and interesting that I insert 

 them here. The right testis and vas deferens are much larger 

 than the left. The lower part of the right vas deferens, in 

 all the adults examined, is much more dilated than the left, 

 and is filled (as is also the external part of the duct) wuth very 

 large spermatophores of peculiar form. The left vas deferens 

 is slender, much as in Eupagurus hernhardus^ terminates in a 

 small opening in the left coxa of the last thoracic somite, as 

 in ordinary Paguroids, and contains spermatophores some- 

 what similar in form and size to those of Eupagurus hern- 

 hardus. In alcoholic specimens of the larger and more 

 abundant of the two species, the spermatophores from the 

 left vas deferens are approximately 0"16 millim. long and 

 0"035 millim. broad, with a slender neck about a third of the 

 entire length, and a very tbin and delicate lamella for a base. 

 The spermatophores from the right vas deferens are over 

 2 millims. in total length ; the body itself is oval, approxi- 

 mately 0*40 millim. long and a third as broad ; at one end it 

 terminates in a very long and slender process, two or three 

 times as long as the body ; at the other end there is a similar 

 but slightly stouter process, a little longer than the body, and 

 expanding at its tip into a broad and very delicate lamella, 

 approximately 0'35 millim. long by 0*20 millim. broad. The 

 contents of the two kinds of spermatophores are, of course, 

 not in a condition to show the structure of the spermatozoa ; 

 but they present a similar appearance in each case, and are 

 apparently of about the same size. 



The most interesting of the Macrura is, perhaps, a new 



