350 Dr. H. Koeliler on the Littoral Fauna of the 



presents some small unequal lobes ; its posterior margin is 

 separated from the branchial region only by a slight trans- 

 verse furrow. The region of the body which succeeds the 

 collar is rather deeply excavated on the dorsal surface ; the 

 groove which is observed here, and which is very deep beyond 

 the branchial region, becomes gradually attenuated behind, 

 and disappears a little before the hepatic region, where the 

 body is nearly cylindrical. The branchial region is about 

 yV inch long. On its dorsal surface it presents an elongated 

 triangle, of which the apex is directed backwards, bounded on 

 each side by a slight groove, and presents in the middle a 

 deeper longitudinal furrow, from which there start laterally 

 some small and very faintly-marked wrinkles, more numerous 

 than the lines of separation of the body-segments. 



The hepatic cfeca, about forty in number, are simple diver- 

 ticula of the intestinal wall independent of each other. The 

 posterior region is irregular, more or less lumpy according to 

 the quantity of coarse sand which it contains. 



This Balayioghssus, like all the species of the same genus, 

 secretes a very abundant mucus from its cutaneous glands. 

 It is well known that the mucus of the Balanoglossi possesses 

 a peculiar odour and that this odour varies with the species. 

 Thus a species found by Giard at the Glenans Islands, oppo- 

 site Concarneau, B. Robmit, secretes a mucus which com- 

 municates to alcohol a strong odour of rum. In the species 

 from Herm this mucus possesses a very marked and perfectly 

 characteristic odour of iodoform. This odour is extremely 

 persistent ; I have recognized traces of it even in specimens 

 of which the spirits had been changed several times. 



As this Balanoglossus differs in its characters from all 

 the species hitherto described, I have given it the name of 

 B. sarniensis, with reference to the locality where I found it. 

 In a note communicated to the Academy of Sciences M. 

 Pouchet has indicated that this Balanoglossus was certainly 

 identical with one of the two species found at the Glenans 

 Islands. As these two species have never been described, I 

 have retained for the Herm Balanoglossus the name that I 

 gave it. The description and figure which I give will enable 

 the identity of the Balanoglossus of the island of Herm to be 

 established hereafter, when the species from Concarneau shall 

 have been studied and described in detail. 



Balanoglossus sarniensis appears to exist over the whole 

 extent of the beach, but it does not seem to be very abundant 

 there, for by digging in the sand for two hours (that is to say 

 during the period of low water) I have hardly met with more 

 than two or three specimens. There is nothing, however, to 



