MUSEUM OF COMPARATIVE ZOOLOGY. 83 
each ; and still lower down are from five to seven additional transverse 
series, extending well down on the ventral surface of the body. It is 
possible that these lateral series are derived from a segmentally arranged 
type; but if to they have certainly deviated greatly from the typical 
arrangement, as they also vary both in the number of series and in the 
number of papille in each series. The papille here are considerably 
smaller, on the whole, than those of the head. There are, finally, a 
number of papille scattered around the bases of the fins, both pectoral 
and pelvic. 
In Clevelandia there are about twenty-five transverse series on the 
sides of the body very uniformly segmentally arranged, being situated 
on the inter-myotomic septa. The series contain an average of about 
five papille each, though the number varies considerably. I have 
worked out the precise arrangement of the series on the septa, — for 
not quite all the septa have papille,-— and of the number of papillze 
to each series in a considerable number of specimens, as it has appeared 
to me that this may have considerable morphological significance. It is 
not necessary for my present purpose, however, to give the results in 
detail. It is worthy of mention that the transverse series on the body 
of Clevelandia are situated in shallow ditches, the anterior wall of these 
being deeper and more abrupt than the posterior. In no case have I 
been able to find the papille situated in canals, or in grooves that 
approach canals, as is so common in fishes, and is said to be the case in 
Gobius niger, by Merkel (’80, p. 28). All writers agree, however, that in 
the genus Gobius by far the greater portion of the papille are free on the 
surface of the body (F. E. Schultze, ’76; Merkel, ’80; Solger, 80). We 
know from the last two of these authors that both the genera Gobius and 
Gobiodon have free transverse series of papillz on the sides of the body. 
With reference to this subject, Solger (’80, p. 378) says: “Bei Gobius 
konnte ich ‘Querreihen von 3-7 Organen’ constatiren ; auf Beziehung 
der Organreihen zur Metamerie des Leibes achtete ich damals leider noch 
nicht. Auch Gobiodon hat am Rumpfe freie Seitenorgane, die in Quer- 
reihen auf Coriumpapillen stehen und héclist wahrscheinlich durchweg 
segmental angeordnet sind.” And Merkel (’80) shows three of these 
series in his Figure 4, Taf. IV. 
It being, then, evident that so many of the near relatives of Typhlo- 
gobius are provided with sense papilla on the sides of the body, the 
question at once arises whether any are found in the corresponding 
region on the blind fish. Very naturally it was to the smallest speci- 
mens in my possession that I turned to begin the search for them. On 
